Fwiw, i use 'AdGuard for Windows' which i can't praise highly enough but that's a paid for product... i think it has a trial period if you want to try it, but i could be wrong on that.
They also have a standalone browser extension that i believe is free for browsers including Edge, Firefox, Chrome and more.
This is the direct link to the Firefox extension download page if you want to read more about how it works on Firefox, it claims that the browser extension can block YT ads but i can't verify that because i have AdGuard for Windows installed which does the same and much more.
https://addons.mozilla.org/en-GB/firefox/addon/adguard-adblocker/Quote:
About this extension
AdGuard ad blocker effectively blocks all types of ads on all web pages, even on Facebook, YouTube, and others!
What AdGuard ad blocker does:
1. Blocks all ads: video ads (including YouTube video ads), rich media advertising, unwanted pop-ups, banners and text ads (including Facebook advertisements);
2. Speeds up page loading and saves bandwidth, thanks to the missing ads and pop up windows;
3. Blocks many spyware, adware, and dialer installers;
4. Protects your privacy by blocking common third-party tracking systems;
5. Protects you from malware and phishing.
...
One of the things i really love about AdGuard is the speed that they update their filters, it's often within minutes of the likes of YT changing their adblocker detection processes... meaning that while many are seeing the stupidly annoying 'you have an adblocker installed message disable it to continue', i very rarely do.