If we take the majority of internet users, in that 99% doesn't care about ad blocking. They are not even aware of extensions and stuff. And most people in that category are not going to notice these changes at all as most of them are chrome users.
Some firefox fans will go to any extent to praise firefox by lying about chrome. One thing is that firefox is faster than chrome. My potato pc with 2gb ram and pentium dual core is able to run chrome (without ad blocking) faster than firefox. Page loading etc is faster even with ads in chrome. Same in my work pc with i5 11th gen and 16gb ram. Other chrome browsers like vivaldi and brave are even faster.
But do I care about a few seconds of lag in firefox?. No. I use firefox because of extensions and ad block integration. Not because of its speed. I also use chrome for banking websites etc for a smoother experience. Firefox has some more to do to get a smoother experience. Especially on phones. Pc firefox and chrome are almost similar. Even then chrome is a little bit more faster to be honest.
Other than people who are aware of this issue, that is a very small pool of people no one is ditching chrome.
Does anyone really claim that Firefox is faster than Chrome. There are certainly reasons to use Firefox over Chrome, but speed isn't one of them imo. I've always found it to be slower.