Personally, I don't really see the value proposition in being able to load and serve you ads faster, compared to a browser with a proper ad blocker.

I don't know what you mean; uBlock Origin Lite blocks every ad on any page I visit in Safari and Chrome, even YouTube ads. Safari also blocks tracker cookies by default, and is significantly faster than Firefox in my use.

The average user does not care about ads being present. Speed is paramount.

Shouldn't getting rid of all the ads make things notably faster?

It does. Fundamentally.

I disagree. I have installed adblockers on different relatives machines. Without fail, they mentioned how much better surfing now is.

They did not not mind the ads, they just didn‘t know there is an easy way to get rid of them

You are radically underestimating how much slow web performance is caused by the massive volume of ads and user tracking data attached to each site.

I hear this complaint all the time, but I just don't see it as having any basis in reality. I use Firefox, Chrome, and Edge side by side all the time, and I never experience any difference in page load times except on YouTube, where we all know that Google purposefully delivers a slower experience for Firefox users.