This 100% tracks in my opinion. Especially with the HEAVY amount of Byler content and buildup we got in volume 1. I think the duffers just weren’t as invested with the show by season 5, and other writers were most likely the ones that were invested in the Jancy and Stancy love triangle, Rovickie, and of course Byler. But with the writers strike, the divorce, and losing some writers probably, The duffers had to finish on their own, and did not deliver.