It obviously can. My first sentence was "uBO already runs on iOS." You asked if Orion was compatible with "normal desktop Firefox and Chrome extensions." There's no distinction between desktop Firefox extensions and mobile ones! Addons on both are just standard WebExtensions, and I've already noted that it runs both Chrome and Firefox extensions.
Your lack of understanding of what browser extensions are is exactly why it would be better if Apple explicitly banned browser extensions from the App Store. Ignorance is a malware vector, and even you, a commentator on Hacker News, do not understand the browser extension ecosystem. Instead, they're taking a bunch of flak for something they aren't even doing, all the while iOS has had a browser supporting uBO for years.
https://wiki.mozilla.org/WebExtensions
Your lack of understanding of what browser extensions are is exactly why it would be better if Apple explicitly banned browser extensions from the App Store. Ignorance is a malware vector, and even you, a commentator on Hacker News, do not understand the browser extension ecosystem. Instead, they're taking a bunch of flak for something they aren't even doing, all the while iOS has had a browser supporting uBO for years.