Initially that was one of the things that kept me away from pathfinder initially was the sheer amount of material was a little much to take on board.
However you can do most of the things you want to do from the core book.
That's from a player perspective, still a little wary of running games as there will come a time where the person who has a pile of books will want to run something I don't know. Because the amount of material in 3pp and even from the expanded core options means there can be a pretty steep learning curve.
Just my 2c.
Cheers