The settings for volume, speed, quality, whether to show/hide recommendations, disable autoplay, etc can be controlled and without requiring any login. Also less cruft. On YT proper such things were only possible with userscripts/addons which ime by the time I found Invidious (2020) had already been broken by YT changes so it was an easy switch when used with a browser addon that auto redirects.

Videos can also be optionally proxied in some instances but that wasn't a draw for me.