Initially i assumed it was cause of all the issues but seeing alllll the plotholes and continuity errors they left…its very possible all the proof for the hopeful ending is possibly just errors the duffers werent good enough to fix.
I honestly wouldn't know. I heard that the show was based off books and each season was a different book, and that they kinda just picked some in different order and just did it and made it work. Not sure how true that is though.
I get what you mean though. The last season did had a lot of random things that never got explained why it happened that way. I'm actually contemplating watching it again just to make sure I didn't miss anything.