I agree. What is stopping me is primarily the metadata stuff. For example, Sonarr runs a closed-source service called Skyhook which exists to make efficient use of TheTVDB. Since Sonarr is free open source software maybe they don't have to pay (looking at https://www.thetvdb.com/api-information and https://opencollective.com/sonarr).

My dream app is split into two parts. One that serves podcasts, music, books (with OPDS so I can browse my library with KOReader), tv, movies, other multimedia (youtube, whatever else). The other handling the metadata APIs and downloading files from different sources (torrent trackers, torrent DHT, nntp, etc...). Sort of like uber-Jellyfin + uber-Arr.

I guess I can probably get a personal API key for TheTVDB, etc... and develop my own sort of proxy and it wouldn't be so bad. Hmm...