I stopped playing the game a year ago, but while I played it I had a lot of fun.

In order to get new meta cards you need to buy packs, spend coins at the card trader, or get them from NPCs in events.
Most of the time you'll be getting them from packs and you need to buy them with a special currency called gems, now this already sounds pretty bad as nearly all games with this kind of set up.
You're thinking "oh boy, I can't wait to spend a ton of money to get in game currency to actual play ANY comp." Cause that's how every mobile game and especially card games are now a days outside maybe getting 1$ worth in events every year. And while you can spend a ton of money to get the very best decks buying tons and tons of packs, there's a difference
A huge part of Duel Links where it really sets itself apart from other card games is that you can get a TON of gems completely Free-to-play and you don't have to devote yourself, checking everyday around the clock like I did (but you can certainly get a lot more that way).
Almost every week there's a different event, seemingly a new one every month, where you can battle special NPCs to get gems which also give you these specific tokens for the event which you can exchange for exclusive event cards at a special card trader OR turn them in to battle the boss of the event at different difficulties for chances at a ton of loot including rare event cards, other items, and tons of gems.
How you spend your gems on the right packs where it counts and looking into cards to make a future deck is VITAL. and allows you to take your F2P against people who throw money at the game and just copy other peoples decks.
Making these jerryrigged decks that you battle with over and over, seeing exactly which cards you use the most, the least, and then slowly destroying, adjusting, and adding new cards that you get from occasionally packs as your scrounging for gems is the meat of the game. But you end up with these decks that are so personal to you, decks that at face value look awful and imbalanced until you play them. and the best part is that they just somehow work and you beat the ♥♥♥♥ out of little timmy who stole his parents credit card and bought 150 packs from the latest set and made a deck from a set list online.

It is one of the most satisfying feeling.

I only spent maybe 10$ ever after playing it for 1 and 1/2 years straight EVERY DAY.

But then eventually the game started ruining itself,
Devs were making their decks with these OP cards and combos and just NEVER patched them cause they'd be sacrificing their rank. (or at least it felt like it). And suddenly this option and play style of these F2P decks were thrown out the window as decks like:
Silent magician, where you had a card that gave a card an additiaonal life EVERY ROUND and EVERY BATTLE, getting more ATK and DEF every stack
Koa'ki, the literally spawn of satan, every card in the set is complete OP garbage. Everyone who actual used this needs to be put in jail. I hate you.
Six Samurai, where you would play one card and do some ♥♥♥♥♥♥♥♥ combo that allowed you to constantly play monsters in and out of hand/graveyard/deck over and over again until you had a full party of monsters all over ~3000ATK in one turn with even more OP abilities. And then the deck had even more OP spells and traps.
That one ♥♥♥♥♥♥♥♥ Phoenix thing, whose name I mental blocked out for my head out of pure misery, you're in the box forever. Bye-Bye.
And finally the Scrap deck, which would destroy ANY of your monster, switch it out with a monster with 100ATK on THEIR turn and then kill it with a monster with ~3000ATK and kill you in one turn.
Also in an honorable mention are these trap cards which adding ONE ALONE would raise your entire deck up a rank. Like Treacherous Trap Hole, Wall of Disruption, Power Of The Guardians, Floodgate Trap Hole, and a few others. ALL of which could only be gotten from PACKS at very rare rates. Especially screw Wall of Disruption, people who use this card deserve the Koa'ki treatment. Users of both need to be put in a gulag with no chance of escape. Please stop.

The meta got so bad that there was no where for F2P players like me could exist in comp outside of one the lowest ranks unless you played OVER and OVER again hopping to get jimmy from down the street you was playing with random cards and just lucked by and get into gold rank.
They even NURFED decks like Aromage which was a really good F2P deck where you could get almost all the cards outside packs, boxes, and even events and instead get the real meat of it from the daily card trader's line of cards. But ALMOST never do I remember a nerf to any of these OP Pay-to-win decks these people found online. Except one time with the Koa'ki deck when it was introduced where Koa'ki Meiru Maximus and Diamond Core was the most powerful combo in the game that ANNIHILATED every other card. I just want you to imagine how bad this card was prenerf was if stuff like the decks listed above were allowed to exist without any interference. Just imagine.

I don't think I can ever come back to this game again, but the good times I had I don't think I'll ever forget.