It is a well-known thing that browser adblockers often fail to play nicely with YouTube these days. However, even if you paid for Premium Lite, Google says it will soon push even more ads.
Edit: Guys. I think a lot of you missed where I said EASIEST METHODS.
Easiest methods to ditch Youtube ads:
PC: Firefox + uBlock Origin
Mac, option 1: Safari + AdGuard
Mac, option 2: Firefox + uBlock Origin
Android, option 1: Youtube ReVanced (FYI: ALL Play Store listings for this are fake; the official site is revanced.app and is the only place to get it)
Android, option 2: Firefox Mobile + uBlock Origin
iPhone/iPad: Safari + AdGuard
For those who may have heard about Pi-hole and are wondering why it's not on this list: PI-HOLE DOES NOT BLOCK YOUTUBE ADS. IT NEVER HAS AND NEVER WILL.
I tried Freetube for a while, but it just never works. An actual coin flip each day whether or not anything would load at all. I got so tired of it I just went back to Youtube, as I've only ever seen one single ad in my entire time using uBlock Origin on Librewolf.
I use it consistently with few issues. Once in a while, usually on Thursdays (when it seems YT rolls out changes), something breaks, but the devs are quick to fix it. The last issue I experienced was when YT transitioned to SABR, and it was out for a day or two before they had things working again. I am at least perfectly capable of going without for a day once every two months.
It's also one of the projects I've used to learn more about how fixes are worked on in FOSS. I will typically run nightly builds also - I find it pretty cool to follow an issue and once they push a fix I can instantly grab that fresh build without waiting for it to be packaged.
If you want to give it a try again, get mpv and yt-dlp installed in your system then activate from Freetube settings the external player button, which you'll be able to click from search or from a vid page
Revanced uses microG, which is optional. I also mentioned that these were the easiest methods. But, you're absolutely right in that there are plenty of other methods to choose from.
No Grayjay? Been using that almost exclusively since they released the desktop version. Had to log out and back in with my (new, basically blank) YT account a few times after updates, and there are very rare cases of certain videos not wanting to load, but overall it's been working well so far.