True, but some of those are much more work for the DM than others, which disincentives going that route.
The rest economy is an easy one.
Components is not, and is also more work for the players, and on a frequent basis - but if you want to make more of the game about acquiring components, that could be interesting.
I would not want to go through all the feats and decide which ones are okay - or trust my players to consult the list I made!
Same goes for spells. No way am I going through all that, or having to constantly remind players what's not on the list.
Restricting multiclassing and certain subclasses sounds significantly easier.