The CS2 update made the game much worse.
Even after almost half a year there are still many problems and bugs - for me, the most noticeable one is invisible pixels which prevent you from getting on the top of some objects - on de_mirage it's ticketbox and top of catwalk. Developers aimed to fix bugs in Source 2 that were rarely encountered by common players and mostly used intentionally, such as airstucks, pixel walks, and silent jumps. These techniques used to be an indicator of a player's game knowledge, which I appreciated. To cut it short, CS2 has these invisible pixels scattered everywhere. When you run in close quarters, you can get stuck in a wall and end up getting killed or losing important timing. I feel like encountering these invisible pixels has become more common in CS2 than in CS:GO.
On the other hand, several gameplay improvements were made - a new smoke grenade system, a new buy menu and the grenade camera in game with bots. In my opinion, they could have introduced a complete Practice mode, eliminating the need for players to set up a server for practice.
The new ranking system doesn't make sense. If you manage to get 25000 points (which might land you in the top-100 players) in Premier mode, you will play against hackers literally every game. The top-100 Premier mode leaderboard is dominated by hackers, rendering the addition of a leaderboard pointless without adequate anti-cheat measures in place. They implemented competitive ranks for each map, where players need to win 10 games per map to receive a rank for that map (requiring 90 wins to cover all maps). However, these competitive ranks are flawed, and the competitive matchmaking balance is broken. Despite achieving the highest (18th) competitive rank in CS:GO, in CS2, the highest rank I got after 70 wins was GN 3 (9th). There are also rumors that getting a rank above DMG (14th) is impossible, regardless of the number of games won. In about 150 games played, the highest rank I encountered was MGE (12th), and this happened in only 2 times out of all the games played.
The new sub-tick system is awful. In short, it sometimes fails to register shots accurately (a problem that seems to have become more common in CS2 than it was in CS:GO). The only benefit of this system is consistent grenade trajectories. Although there was a recent update aimed at improving shot registration, I personally didn't notice any difference.
Graphics have been significantly enhanced, and many maps have been updated. However, the new graphics feel cartoonish and plastic, especially the weapon models. As for me, CS2 is TOO bright. A recent update changed the Steam inventory icons, but in my opinion, they now look terrible.
The other CS2 problems are related to console and server plugins. They added console autocompletion, which unfortunately cannot be disabled and does not work with aliases. Upon transitioning to Source 2, all previous server plugins became incompatible, forcing plugin creators to adapt to CS2 and recreate their plugins from scratch. Additionally, the old VGUI menu utilized in previous plugins has been replaced with an inconvenient menu system controlled through the text chat.
In general, I believe Valve could have implemented more new features without discarding the old ones. A part of the community with low-end PCs has abandoned the game because of the new graphics. Third-party platforms with their owns anticheats like Faceit remained the only way to show your skill.

The CS2 update made the game much worse. Even after almost half a year there are still many problems and bugs - for me, the most noticeable one is invisible pixels which prevent you from getting on the top of some objects - on de_mirage it's ticketbox and top of catwalk. Developers aimed to fix bugs in Source 2 that were rarely encountered by common players and mostly used intentionally, such as airstucks, pixel walks, and silent jumps. These techniques used to be an indicator of a player's game knowledge, which I appreciated. To cut it short, CS2 has these invisible pixels scattered everywhere. When you run in close quarters, you can get stuck in a wall and end up getting killed or losing important timing. I feel like encountering these invisible pixels has become more common in CS2 than in CS:GO. On the other hand, several gameplay improvements were made - a new smoke grenade system, a new buy menu and the grenade camera in game with bots. In my opinion, they could have introduced a complete Practice mode, eliminating the need for players to set up a server for practice. The new ranking system doesn't make sense. If you manage to get 25000 points (which might land you in the top-100 players) in Premier mode, you will play against hackers literally every game. The top-100 Premier mode leaderboard is dominated by hackers, rendering the addition of a leaderboard pointless without adequate anti-cheat measures in place. They implemented competitive ranks for each map, where players need to win 10 games per map to receive a rank for that map (requiring 90 wins to cover all maps). However, these competitive ranks are flawed, and the competitive matchmaking balance is broken. Despite achieving the highest (18th) competitive rank in CS:GO, in CS2, the highest rank I got after 70 wins was GN 3 (9th). There are also rumors that getting a rank above DMG (14th) is impossible, regardless of the number of games won. In about 150 games played, the highest rank I encountered was MGE (12th), and this happened in only 2 times out of all the games played. The new sub-tick system is awful. In short, it sometimes fails to register shots accurately (a problem that seems to have become more common in CS2 than it was in CS:GO). The only benefit of this system is consistent grenade trajectories. Although there was a recent update aimed at improving shot registration, I personally didn't notice any difference. Graphics have been significantly enhanced, and many maps have been updated. However, the new graphics feel cartoonish and plastic, especially the weapon models. As for me, CS2 is TOO bright. A recent update changed the Steam inventory icons, but in my opinion, they now look terrible. The other CS2 problems are related to console and server plugins. They added console autocompletion, which unfortunately cannot be disabled and does not work with aliases. Upon transitioning to Source 2, all previous server plugins became incompatible, forcing plugin creators to adapt to CS2 and recreate their plugins from scratch. Additionally, the old VGUI menu utilized in previous plugins has been replaced with an inconvenient menu system controlled through the text chat. In general, I believe Valve could have implemented more new features without discarding the old ones. A part of the community with low-end PCs has abandoned the game because of the new graphics. Third-party platforms with their owns anticheats like Faceit remained the only way to show your skill.