Season 1 is absolutely fantastic. Perfectly paced, great reveals and action, fun characters...itβs a blast. S1 will always be the GOAT.
S2 overall had some really great stuff (such as the villain story, that was actually pretty amazing imo), but most of it was only 'good'.
S3 felt like it could've been something until Savitar showed up. S4 has been pretty 'meh' so far, except I missed quite a few episodes.
So, in general, I think the show has greatly decreased in quality... however, I still enjoy it most of the time. The cheesiness lately hasn't really worked, but sometimes it does.