As the admin for various SMBs I cared only in a vague, way whether their browsing experience was made unpleasant by ads.
I cared enormously whether I had to spend valuable time imaging or de-rooting their PC because some 0-click infection delivered by ad-network ransomwared us.
I have never felt even the slightest obligation to the vague collective of websites that rely on the shockingly dangerous concept of injecting unvetted, advertiser-supplied code into trusted domains.
From the moral angle, paywalls are an option and were in fact heavily used 25 years ago. The decision to rely for revenue on whether and in what manner a browser renders certain elements is certainly a choice a site-operator can make but it creates neither legal nor moral obligations on me or my users. My obligations as a paid IT / security practitioner are rather clear, and they are to my employers and clients.
I do not know the latest numbers on "what percent of web-based (or all) infections are mitigated by adblocking", but based on historicals that it is well over 50%. In that context it is lunacy to ask "but what about the site operators who create this mess".