Should that have ended Stranger Things?

Let me start off with the what is indisputable - season four was the best season of Stranger Things. This was a riveting, thrilling, creepy ride of a season that satisfied on almost all levels. During the final episode (movie?) of the season, it felt strongly that the whole thing was about to wrap up. Then at the very end, a few pieces were left dangling so that a new, final season could be made. But should it have ended? Would it have been the perfect place to do so? Spoilers below.

Unlike the last season of Billy, this season satisfyingly tied together loose plot threads and finally, finally gave the show some reasons for everything that had come before it. The unveiling of Vecna as 001 was a great reveal that immediately gave the show a boost of emotional connection, and that was followed with the reveal that Vecna was the one responsible for all the other "upside down" occurrences that happened in earlier seasons. He became the ultimate villain responsible for all that has befallen the kids and Eleven became the ultimate hero (the only one who can stop the villain). It was a very nicely done set-up, it upped the emotional connection, it joined all the storylines together, and it led to a huge, "final" confrontation that resulted in the apparent death of Vecna and Eleven and the other kids saving the world. The End. Satisfying on all ends and the series would be remembered as a the best series Netflix has ever done.

Until, in the final moments, they (meaning the Duffers or Netflix or both) decided that Vecna would not be dead, Max would stay in a coma, and the upside down would come crashing through the cracks. It felt like a cash grab. A desperate move to make sure there would be another season, more merchandise, anything (and I mean anything) for Netflix to promote, etc.. It felt like the perfect way to end the series and it was suddenly broken up with a few minutes left in the final episode.

Now, maybe the final season ends up being even better, but I do not have high hopes for that. I think it was a mistake by the Duffers and Netflix to not end it right there. But, who knows... stranger things have happened.