For me the answer is quite simple: it's the only browser on iOS that lets you run Chrome extensions and Firefox add-ons.

It could run extensions a lot better if it ran on other platforms, so the extension developers could actually test it and support it properly.

I'd love to support Orion, but I can't because I don't have a practical way to run it.

Doesn't Firefox also run Chrome extensions? Not that Firefox doesn't have enough extensions by itself...

Firefox on iOS doesn't support extensions at all.

Firefox on any platform does not run Chrome extensions, because it is not built on Chromium.

having written a few extensions... they are basically the same API with a few differences you need to account for. there's polyfills that can unify the experience a bit more too.

The underlying APIs are very similar, but you can't just install an extension from the Chrome Web Store.

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