Season 1s are great, setup, some payoff, a bit of lead into the overarching story. Then season 2 to X. The heroes win and then lose in the final episode, cliffhanger to next season. People get bored. Final season is announced and they wrap up the show.
I agree with your assessment of the most recent season finale, but I would say in general every season has done a good job of having something cool happen in every episode. Like in the sense that each episode has a complete narrative arc. That’s not to say that the whole show doesn’t tease you a bit, but the individual episodes still have satisfying stories.