LibreTube - uses Piped as video source by default. Subscriptions and playlists can be created, all without actually interacting with YouTube.
Clipious - uses Invidious as the video source. Also allows for subscribing and accounts. Lesser known client
NewPipe - Gets the source directly from YT. Allows for subscribing and creating playlists
Additionally, there’s also ReVanced that lets you patch the regular YT app to include useful features.
Web Video Caster can cast to a large number of devices, Chromecast included. It has a lot of companion apps too on several smart TV platforms, all for the sake of getting your media played back on another device.