Also plugging Firefox mobile here if you do any web browsing from mobile. You can add uBlock Origin on Firefox mobile, which you can't do on Chrome mobile.
From a quick web search, while it supports installing firefox plugins they may not all work as expected due to limitations/differences in the browser APIs, and ublock origin fails to work properly as a result.
So IMHO mozilla are probably choosing "Let's not" rather than "Let's deliver a broken experience"
As one user on reddit said - "Orion supports Firefox and Chrome extensions. Yes. And you can install them. Yes. Do they work, though? No, most of them don't. Orion is lying about their extension support. "
Safari is limited in the same way as Chrome manifest v3, allowing basically only a URL blacklist. They're crippled compared to uBlock Origin's various other blocking capabilities.
I’m also going to add for now you can still manually install ublock on the latest chrome by downloading it from GitHub and installing it under manage extensions. For now.