The internet has changed how hard it is to find fish on big public lakes without question.
If you do some googling on recent tournament results, especially if B.A.S.S. or MLF has an event on a particular lake, you can usually find all the info you need to find good fishing spots.
Then you have the whole "community holes" aspect, go into any local tackle shop, or be friendly around the boat ramps, and most times knowledgeable anglers will freely share the community holes because after all, they're community. Anybody who is competitive on a particular lake will already know those places, no use in keeping them secret.
A huge reason why the most dominant anglers in the sport are 18-25 yrs old is the fact they didn't have to spend decades like Rick Clunn learning every single major Bass fishing lake in the country. These kids show up to lakes for the first time with a graph full of waypoints. A graph full of waypoints and copious time using FFS are the main ingredients to winning on the top levels of professional fishing these days.