1st season was a lightning in a bottle. It hit just at the right moment to capture 2 demographics at the same time: Those who have real and those who have fake nostalgia for the 80s (zoomers in this forum going on about their cringe ass vaporwave hahahaha)
Season 2 and 3 were really bad cash grabs.
Season 4 was better again. Still not as good as 1 but way better than 3 and 4.
At its core it's character driven. The casting for the roles was perfect.
It's good. Not a masterpiece of writing but still one of the more enjoyable things Netflix shat out.
I share a similar sentiment basically, I personally think the show should have stopped at season 1, because I feel like one of ST's strong points is the child like wonder and reasoning of a serious and deadly situation, now that they're teens (and the kid actors are reaching their 20s) it's just doesn't have the same spark anymore. It has a moments for sure, but like what you said it's a lighting in a bottle situation.
Supposedly there's gonna be a time skip in season 5, but I don't think that's gonna make anything more interesting.
ST has a bad habit of picking up interesting characters and then killing them off by season's end, also the duffer bros seems to have a hate boner towards the jock/popular kid archetype since those are the characters that get the worse end of the stick when it comes to events on the show, while the nerd/freak kids are idolize. Idk it's just really repetitive
Anyways, I say the show should have ended at season one, and would have totally forgot about it if it wasn't for the dude who plays Billy in seasons 2 and 3 being the total opposite of his character in real life.
I didn't expect him to be a one to one of his character, not any GOOD actor is, but I just find the idea of him having a scene with one of his co-stars where he's being super mean, then the camera's cut, and he's like "Oh my gosh are you okay? I didn't hurt you, did I?" To be really funny and sweet.
While I didn't think much of his performance at the time of watching season 3, after reading some interviews you could tell that he really gave it his all in his performance.
Plus he's easy on the eyes, but I only say this after watching and reading interviews about him, his character in ST does nothing for me by himself.
In conclusion, I'll watch the final season of ST, just to see how it all ends, I have a mighty feeling it's gonna go down the same way GoT did, still will be fun to watch tho... hopefully