Google can't block ads and tracking scripts in Chrome without either blocking their own, or facing (valid) claims of anti-competitive behaviour. Neither of which would get the person who did it promoted.
And no attempt to fix the slowness of the modern web will succeed without blocking ads and tracking scripts.
This is the downside of the dominant browser being made by and ads-and-tracking company.
I'm not sure that graph shows what you think it shows.
That graph shows that there's an obnoxiously large number of websites that don't support something that there's zero reason not to support.
It costs $0 and takes maybe half an hour to implement, browsers are screaming "not secure" to each visitor, and one in five websites still don't support it. "Make websites faster", on top of being vague, is way more difficult to implement.
You don't have to convince anyone, it's about incentives. The article and many others have shown exactly how to do this: make the metric a big part of search rankings.
If fast site performance ensures you get listed first, every site would get faster overnight.