According to the news item below, you can remove advertising from YouTube video by add a full stop (period or dot) after a YT videos URL. I.e. So the end of the YT URL would be changed from .com to .com..
Probably a YouTube glitch and likely to be fixed, but would be interesting if it stays as a feature.
See https://www.theverge.com/2020/6/11/21288291/youtube-remove-ads-add-extra-period-url