I've been using for many years now the unhook youtube[1] extension to hide any distracting nonsense on youtube, you can select piecemeal what to hide, like the recommended trash in the sidebar, cards at the end of the video and even the main page. Supports firefox, chrome and edge.
In addition to Unhook, I also use SponsorBlock [1] and Return YouTube Dislike [2].
While SponsorBlock is something that some people might not want/need, I find Return YouTube Dislike to be particularly useful because the like/dislike ratio is a valuable data point for a video I'm about to watch even if it's just an approximate/predicted value.
[1] https://unhook.app/