Basically ad/js blockers elevated to content selectors, somewhere halway between full functionality and reader mode of the core content of a page.
I see a literal tsunami of tiny projects like that on HN and various other places, and I suspect it's quickly gaining the characteristics of a product category — how much would you pay, or give away, to reclaim a distraction-free highly-focused web experience? Not sure about individuals (most mainstream users), but in businesses, offices, on the clock? That makes a stupid amount of sense. ("stupid" because, heh, it's seeking a solution for a problem we created in the first place, businesses deploring the consequences of things whose causes they cherish, should we say champion in modern lingo.)
[1]: not that kind! https://www.pictorem.com/collection/900_Pawel-Kuczynski_blin...
! Block the hot network questions for focus
superuser.com,stackoverflow.com,stackexchange.com###hot-network-questions
! Get rid of the distracting "Blog" area
superuser.com,stackoverflow.com,stackexchange.com###sidebar > div:has-text(Blog)
! This banner reappears for me
superuser.com,stackoverflow.com,stackexchange.com###js-gdpr-consent-banner
! Block the left sidebar that takes up space
superuser.com,stackoverflow.com,stackexchange.com###left-sidebar