This is probably one of the harder ones I've written because I had to keep pulling myself back from going on endless tangents.
Again, I want to stress that if you do storytelling of any kind: make your protagonists matter to the story. Supernatural has had a problem for awhile with making Sam and Dean passengers in their own series, but this season was perhaps the worse because the theme and principle of the season was supposed to be Sam and Dean gaining freedom and agency in their life stories. When we looked back at the season, we should have seen that it was Sam and Dean and ONLY those two who could have beaten Chuck and got Jack to where he is now. As it is, the only reason they did was literally because Chuck personally favored them.
Or you know, instead of doing god, again (because that's what S11 was - fighting an evil god), do something else. Evil Winchesters. Heck make Mr. Goo the main villain and have the final season be all the main villains teaming up and being brought back in a massive allied force. Or be really daring and don't have an arc. Let every episode be a MotW episode with a special guest star/friend showing up to get a send off - like 15.10 "The Heroes' Journey" but for more people than just Garth.
Before I was into Supernatural, I was a trekkie. I grew up watching Star Trek: The Next Generation (TNG) and Deep Space 9 during that golden age of science fiction: 16. I keep thinking about those shows' endings compared to Supernatural's. TNG was much more episodic with continuity episodes being memorable for how rare they were. So the final season was mostly like the rest of them (other than the writers seemed to have run out of ideas) - random stories here and there, with an amazing final episode that was a perfect bookend with the premiere episode and a look back at the show as a whole.
Deep Space 9 was actually far more like Supernatural as it was one of the early shows to really start leaning into long form storytelling. There were a lot of AotW (anomaly of the week) episodes to fill out the season, but there were more and more arc episodes each season as well. As time went on, DS9 began to lean far more into it until, in the final season, they needed a massive 10 episodes to finish wrapping up all the storylines and end the show. 10 episodes out of a season that had 26 (well... the last episode is kind of a 2 hr - #25 & 26 combo). That's nearly half of the season. You can't remove or change a single one of them without massively damaging the finale.
So I keep thinking about and comparing that to Supernatural. Especially since COVID disrupted all their plans and gave them extra time to wrap everything up, I can't help but wonder why the last arc wasn't all 6 of the remaining episodes. Especially when you compare it to season 5 and... well you could argue it had a build up of 7 episodes to its finale.
Check out my previous interviews and reviews to learn more about storytelling in and around the Supernatural universe!