Plex has been baking in features like that to help you see what is on other streaming channels, etc..

Personally the whole point of Plex for me was it was a container for my existing DVD/Blu Ray collection, while Plex has added some really cool features. Increasingly they keep resetting the dashboard to try and force engagement with new features, it feels a bit user hostile and I've been switching to Jellyfin (same idea but entirely open source and self hosted).

From a discovery perspective, personally I've found good content tends to create its own word of mouth style buzz.

For example at the moment you can't go near twitter, reddit, work, BBC News, etc.. without someone talking about 'Mr Bates vs The Post Office'. Recently the risa community kept mentioning Babylon 5 so I picked up all 5 seasons for £20 and watched it through. Similarly the Risa community really seems to love Star Trek prodigy so I'll probably give that a go at some point.

It's not as convenient but it's more socially healthy in my opinion to rely on word of mouth. Since I've started pirating all of my content and streaming through jellyfin, I've found that I'm talking amongst all of my friends more about their interests in docs, shows, movies, etc. I didn't realize how much social commentary had been replaced with algorithms until then.

I follow a couple of youtube channels that do TV and movie reviews, those usually cover the highlights (good or bad).

Other than that I mostly check the "recent uploads" section of several torrent sites and piracy discord communities.

Sites like tmdb, imdb, trakt

Personally:
Kinocheck (YT, uploads cinema trailers)
gigguk, Crunchyroll (YT, uploading/reviewing shows) NZB360 (Android app for managing *arrs and my other related services)
Trakt (Website)
IMDB/TMDB (Website, If I visit them)

I just rate my watched shows on reelgood, it gives pretty decent recommendations.

Overseerr