I haven't seen anyone re-evaluate it since Safari added Web Extensions on Mac and iOS a few years back.

Most likely not for same reasons ad blockers were freaked about Chrome's Manifest v3 push - browsers are trying to optimize away the latency from a massive synchronous javascript-based list check on page load, and the privacy risk that comes from these extensions having exposure to every page (and injecting their code into every page). Conversely, the web extension authors don't see the set of limitations as feasible.

But it is odd that uBlock Origin doesn't seem to have even issued a public-facing statement of even evaluating the functionality that is there in Safari.

No. Apple doesn’t let plugins hook in so much because the plug-in ends up seeing a ton of data about what the user browses, and they can slow the browser down if badly written.

Apple lets plugins provide lists of elements/css/IPs/etc to block. Safari processes them and is able to block stuff based on that extremely fast and power efficiently.

There is flexibility lost. Plug-ins can’t see which rules are/aren’t hitting. You can’t filter based on the content of a request.

So there are ad blockers, and they work well. But uBlock, as it works elsewhere (I know it’s considered the best), isn’t possible due to the trade offs Apple chose.

This isn’t true anymore, there are numerous ad blocking plugins that do the extensive blocking just like uBlock. May not be as good due to less active community, but the capabilities are there and a few of them are quite good.