At one particular point it was, if I recall correctly, though Chrome also (mis)implements some standards its own way, so Google might also use that as a form of attack against anyone who implements them properly, much like Microsoft did in the bad old IE6 days...

It's all a silly arms race, though, with Google coming up with new ways to enshittify the web for anyone not using Chrome or using ad blockers and Mozilla and ad blocker (and alternative YouTube frontend) developers trying to figure out what they broke this time and how to fix it, so what worked yesterday might not work today and work again tomorrow.

It's all a profoundly stupid waste of everyone's time and resources (all for a few more ad views) which will hopefully end up with Google losing their monopoly position on the web like the Internet Explorer bullshit did for Microsoft, but will keep being a major hassle for everyone until it does.