5e's 6-8 encounter adventuring day bugs the living hell out of me.
Two things with the adventuring day, though. First, it's not every day. You can go 3 months without one and then have one with 6-8 encounters in it. Second, I engaged the long rest variant so that I could stretch that adventuring day out to a week, so it makes it more palatable, though still frustrating.
As I said, though, if there really were that many monsters just wandering all over, then not even the number of adventurers in the FR could save humanity and the other PC races. They'd have gone extinct millennia ago.