I'm no biologist but most bodies of water are cyclic in terms of fish populations, due to factors such as disease, weather creating poor/exceptional spawns, lack of DO, predation, etc. From what I understand fishing pressure is pretty low on the list.
This fall was pretty crappy in terms of fishing, but has picked up quite a bit in the last couple months. We don't get fishable ice here in MO and the lakes seldom freeze for more than a week so I fish from the boat all year.
This was from a couple days ago. In 2019 and 2020 you had to sort through a dozen dinks to get one keeper crappie on that lake. This year and last, it's been the opposite, hardly any short fish. I think we had pretty lackluster spawns in 2017/2018, and 2019/2020 were excellent due to the high water events.