That it didn’t select everything was only the default on Linux, to accomodate the folks using the middle-click clipboard (primary selection).
But yeah, I don’t remember, if there was a good reason why they removed it. I think, they replaced the URL bar implementation and just have this feature in the new one. So, maybe they’d accept a PR?
Apparently, they’re currently in the process of turning people’s Manifest V2 extension off. They seem to be stretching it out over a few weeks to sidestep a shitstorm.
https://developer.chrome.com/docs/extensions/develop/migrate/mv2-deprecation-timeline#october_9th_2024_an_update_on_manifest_v2_phase-out
Afterwards, there will still be uBlock Origin Lite, but the dev didn’t choose that name for funsies. It will be even worse at ad blocking, and be missing some important features like automatic block list updates and the element picker.