Seems to be the same plot every season

First time watching stranger things and it’s the same thing every season so far. 3 different groups of characters all discover something about the upside down but don’t share it with anyone else but if they literally just came together, they’d be able to figure it out. Is this how season 4 and 5 are? I know a lot of people say season 3 is when ST got bad and I can see that. This season is directed completely different. I feel like this show didn’t even need a season 2. Season 1 was perfect.