It's just so tedious to do by hand, although it's nice to browse without jarring changes to the page as you load.
It would be great if there were some kind of community powered block list that adhered to some kind of standard. Probably easier said than done
As the creator himself says, uBlock Origin is not just an ad blocker, it's a wide spectrum blocker.
Let's use CNN as an example. I load their mobile site with scripts blocked, and I see a menu with links that lead to mostly-broken news sections.
So I allow scripts from cnn.com, and the frontpage loads normally. The links work, and I can even see the puppy bowl headline's gif.
When I check which sites were blocked from loading JavaScript, there are 20 domains: ads-twitter.com, adsafeprotected.com, bounceexchange.com, casalemedia.com, cnn.io (probably okay?), cookielaw.org, etc...
Most modern sites have dependencies that don't really seem necessary. Social media, ad networks, telemetry...whatever those sites want to do, I don't really need it to read a news story.
I know there are people who maintain a browser profile with scripts enabled - for the Twitter's and Indeed's of the world that get upset if you don't have scripts on.