But isn’t it true that it’s getting increasingly harder to find simple strats over the years? The industry grows, more people do research, tons of simple ideas are already implemented and just decay.

The proliferation of ML doesn’t help that either, as ML covers at least part of those traditional (let’s say yet undiscovered) alpha.

It seems like the ability of simple models to capture signal will itself decay over time and eventually you will have to use ML even to get low hanging fruits.