a comparison I’d make is to Fargo
season 1-3 of Fargo are all good-exceptional seasons of tv.. and then there’s season 4.. season 3 was good but not on the level of greatness of seasons 1 and 2
but with stranger things, the weak season is season 2.. but like the wire season 5, there was good in there
season 2 suffered for the same reason ironman 2 and age of ultron suffered in the MCU, trying too hard to backdoor/set up shh instead of doing more with the stuff actually happening
but season 3 is a good rebound and season 4 was great