With a 1 story base you don't have any stairs where the pals can't get up on, so you probably have the problem that your pals can not reach the work bench BECAUSE THE PATHWAYS ARE TOO SMALL!

If you want your pals to get to your workplaces, you need AT LEAST a 2-WIDE PATH. You might want to create a flat surface by placing foundations to make it easier if you haven't already. Between the walls you need a 2-wide path for the pals to reach your workplaces. It's even better if you have a 3+ wide pathway to make sure they never get stuck.

Also, for HUGE pals, make sure one story is at least 3 walls high, this will prevent huge pals to get stuck in the middle of your base.
Hope this helps :)

With 2 stories you probably have the problem that your pals can not reach the workplaces on the second story via your stairs.
If you haven't already, make sure to also implement "1 Story" in your base to make sure they can even get to the stairs.
Make sure a single story is at least 3 walls high, this will prevent huge pals to get stuck even when they don't reach the stairs.

Now, why don't the pals get up the stairs? This can have multiple reasons:
1. Not wide enough stairs
2. No support
3. Wrong type of stairs

1. Your stairs might be not wide enough, I recommend using 3 wide stairs (all the same material).
If this doesn't help, use issue 2:

2. I once had a 3 wide, 3 high stair where my pals wouldn't go up, when i placed a pillar of the same material at each corner of the stairs, my pals would finally get up the stairs without any issues. So try to place pillars on each corner of *each stair* and see if it works.
If this doesn't help, use issue 3:

3. This might sound weird, but it happened to me multiple times. When I used wooden stairs while i had stone foundations, the pals wouldn't even try to get up to the second story. When I used stone stairs and stone foundations, they would actually go up to the second floor without any issues. So try to make the stairs the same material as the foundation under it.

I really hope this helps someone who's pals are stuck all the time or don't get up to the second floor :)