Spoilers for the final season ahead:
The overall pacing of this season was strange, and it felt overstuffed and uncertain of which new storylines it wanted to create, while also failing to properly conclude storylines that came before. The finale is perhaps the best example of this; I felt as if I hadn't seen Otis and Maeve together romantically enough for it to justify the show ending with them parting ways. Had there been more time spent showing them together romantically, there would have been more incentive for me to feel the intended bittersweet emotions the ending was going for. But as there wasn't, I instead felt cheated, as if the four total seasons of their connection was a complete waste of time. I'm not of the belief that showing too little of them romantically in and of itself is what ruined the show, but if that's the direction you choose to go, then a simple "happy ending" in which they stay together is the only instance in which any of their development feels worth it.
TLDR: Otis and Maeve should most definitely have stayed together in the finale, and how the writers failed to see that truly astonishes me.