You need to ask your colleagues to pair with them, and your management to encourage the practice. The amount of institutional knowledge you need in order to thrive should be more fire hose than eyedropper. The reason people fight with their tools? The tools suck in terms of instructions and the only way you master them is to watch others master them.
As soon as you make yourself indispensable (this can take many forms, and you should explore holes in the lineup that you enjoy doing, which may include project tracking, or thoughtful code reviews, or bringing homemade pizza in when everybody's starved and exhausted and can't bring themselves to eat), you're secure. Work as hard or as little as you like, and don't feel bad about it. That's the maximum degree of control you get, with a sizably random portion that will forever be outside your control.
Take some comfort in your idle time and try to push it toward reading or documenting something, even if it's as mundane as your own on boarding experience (in order to make it easier for the next new hire). Try this philosophy: As long as you put in your hours and meet expectations, you're fulfilling your purpose to the company by prettying up the place and using your weight to keep the building from blowing away.