I'll add these to the list if you don't mind:

1. GrayJay for Android
2. FreeTube for desktop and also works on Android.
3. SmartTube for your Amazon fireTV and Google tvs and the likes
4. NewPipe for Android.

I also want to drop Grayjay in here. It supports YouTube and can also be used to view other platforms like Twitch, Odysee, PeerTube, etc. It uses plugins, so you can develop a plugin for the video platform you want to be able to use in Grayjay. Grayjay also has this Polycentric "decentralized" database so that you can comment and like the videos in those aforementioned platforms.

Materialious
PipePipe
Tubular

All I want is an ad-free YouTube app that lets me cast on Chromecast directly.

So far nothing worked properly. Any ideas? I'm using a Pixel 4A.

I've been using pipe-viewer (formerly/alternatively youtube-viewer) for years. It's an extremely minimal yet feature-rich and customizable perl youtube client, designed to be used without a google api key (If you want to use an account, use youtube-viewer instead). No other client I've tried comes close in my experience (I've tried Freetube (bloated), Minitube (buggy, feature incomplete, uses embedded player), Newpipe (restricted to android)).

Also works great on mobile, and can be used with a Gtk-perl client for people who want a graphical client. It can also be used with any native video player, like mpv or mplayer (and adding an unsupported player is trivial in the config).

Demo:

youtube.com + firefox android/fennec + ublock origin + sponsorblock

Using Tubular, which is a fork of newpipe with sponsorblock integration. It's a bit buggy but I like not having to skip every sponsor

I'll also plug SmartTube, an Android TV app that has many of the more widely-used functions ReVanced has (blocks ads, supports SponsorBlock, etc.) among other things.

Wait, revanced works again?

This was me when Invidious and Piped were being attacked by Youtube and Newpipe had a hiatus.

Tubular is a Newpipe fork with Sponsor Block integrated for anyone interested.

I would use Libretube, but it simply doesn't work on my phone. On PC I always use piped.

I'm having great time with FreeTube Cordova lately, you have to setup the UI initially, understanding its limit for mobile, but it works very well.

Libretube seems to almost never work for me no matter what instance i try.
Also worth adding Smarttube for AndroidTV

Tubular: A fork of NewPipe (Github) that implements SponsorBlock (Github) and ReturnYouTubeDislike (Github). https://github.com/polymorphicshade/Tubular?tab=readme-ov-file#a-fork-of-newpipe-github-that-implements-sponsorblock-github-and-returnyoutubedislike-github

Still in development but Lighttube seems interesting and uses its own backend.

But it's still going to Google's server this traffic. I'd like something that is not YouTube but then there are no creators on these other places. Maybe I'll buy one of those nebula/floatplane stuff?