Any reason why Mull is not recommended as Android Browser?

[Xoxohelloes]

Which browsers are best for privacy?

It scores high and it is a Gecko based browser. Any reason why this is not recommended by Privacyguides?

[PoorPocketsMcNewHold]

it is a Gecko based browser.

On Android, Firefox is still less secure than Chromium-based alternatives: Mozilla’s engine, GeckoView, has yet to support site isolation or enable isolatedProcess.

Site isolation of Gecko-based browsers on Android

As we know Gecko browsers don’t have site isolation on Android. I really want to use Mull on Android, but some questions preventing me from switching. Is site isolation a big security concern? Are there many sites out there that can exploit this vulnerability? Should I open only one site per session when using Gecko-based browsers to mitigate the site isolation issue? What threat model is suitable for using Gecko browsers?