Yeah, that’s why you often hear “ads suck”
I know the adsense team said they were working on improving the performance (and making it load async) but it’s been a while since they talked about it (velocity last year). I expect that if they don’t have an announcement or update this year then there’s going to be a lot of questions and pressure (rightfully so since they are responsible for so much of the ads on the web).
The alternatives aren’t really pretty. I’ve seen a bunch of people try to make it load async but there were issues with all of the solutions. You could switch to an ad network that supports async loading but they might not be able to monetize as well. You could remove the ads but that kind of defeats the purpose