If major browsers were 100% user-centric they would've built ad-blocking into the browser. Maybe make it opt-in, but it should be there as a built-in feature.
All of the major browsers (except perhaps Safari?) are built to increase the control of the browser vendor (through profiles and tracking) and web developers (through increasingly intrusive hooks into the OS). All of this at the expense of the user. Users are _not_ given fine-grained control over what websites can do with their computer, and what control still remains is being slowly eroded by changes to APIs and intentional hiding/removal of important privacy settings under the guise of "not overwhelming users with too much choice."
Extensions _should_ be able to help here, but browsers keep slowly marching forward with changes that take away extensions' ability to perform meaningful actions on behalf of the user. Extensions these days are pretty much only useful for turning the browser into an application delivery platform, like the Apple App Store or Google Play. Firefox switched to "web extensions" some years ago, neutering many useful extensions. Google is now switching to Manifest V3 (which Firefox has stated they will adopt), which means the days of effective ad blocking will soon be over.
Extensions _should_ be able to help here, but browsers keep slowly marching forward with changes that take away extensions' ability to perform meaningful actions on behalf of the user. Extensions these days are pretty much only useful for turning the browser into an application delivery platform, like the Apple App Store or Google Play. Firefox switched to "web extensions" some years ago, neutering many useful extensions. Google is now switching to Manifest V3 (which Firefox has stated they will adopt), which means the days of effective ad blocking will soon be over.