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).