Very difficult. It is not just technical but there are business reasons too.
That said, it is possible to make drastic adjustments that help monetization, UX, and still have ads. I did that as a short-lived experiment for a very ad heavy mobile site (SFGate):
Main points are here (not a ton of details) in this sanitized post-redaction deck:
El Diario has to have some kind of crazy loophole. That or some rogue genius has solved a pernicious problem and hasn't shared their wisdom with the world. I see normal google ads and just everything loads so incredibly fast. I'm not a perf expert, but our page speed insights seem to pin almost everything on ads.
That said, it is possible to make drastic adjustments that help monetization, UX, and still have ads. I did that as a short-lived experiment for a very ad heavy mobile site (SFGate):
Main points are here (not a ton of details) in this sanitized post-redaction deck:
https://docs.google.com/presentation/d/12ds0b4nTxzcDy23te0Zm...
I had an extra labeling for non-ad sites so there was some distinction and would like to restore that.
However look at El Diario - ads and number 1 spot!
DotDash has numerous high performant sites (ThoughtCo etc) that have ads too.