I don't know if it's related to Jellyfin becoming a more viable competitor, but Plex has improved a lot recently. Sync/Downloads are better, the TV apps got a much nicer layout. The metadata agents got updated to be faster. I've been pretty happy lately.
The core problem is that Plex is a business, with investors. Depending on pirated content is not a good model for business success, so they’re trying to pivot. IMO Jellyfin has it right: a non profit, open source solution.