[rvschuilenburg]

This would be a fun idea. Especially if this was combined with your watchlist. The website could decide you have most stuff on your wishlist for service X, automatically cancel/subscribe, and send you an e-mail with a summary of what you can watch in the upcoming month.

[judge2020]

This is what Plex has branched into, kinda, although there's no automatic subscription management since no service wants to give up control of cancellations and whatnot.