Generally speaking, if the style of a table just isn't right for you, and you're not having fun, it's better to drop than it is to just carry on attending and feel miserable about it.
However, you may not want to drop in some instances - maybe the DM is a close friend and you want to support them, maybe you don't have any other options for campaigns to join, maybe you've got sunk costs and you're near the end and you just want to see it out, etc..
In that case you could try talking to the DM about it to help them improve... Not in a "hey you suck" kind of way, but in a "Can we talk? I've got some suggestions that might help make the game better" kind of way.
If it's a close group of friends you could try running a side campaign or a mini-campaign yourself, and, provide the group examples where the game runs a little better (not in a "you're doing it wrong let me show you" kind of way, just in a "hey I have a mini-campaign I'd like to run" kind of way.)
Remember that no DM is perfect, and everyone is learning and improving all the time, and that the primary purpose of playing together is to have fun.