LibreWolf is a great privacy oriented Browser for desktop. But there is no version for android or IOS . There are some like mull but they have their own problems. Mobile phones stay with us most of the day. So we need extra privacy for it.
What is per-site process isolation?
Per-site process isolation is a powerful security feature that seeks to limit exposure of a malicious website/script abusing a security vulnerability. Firefox calls per-site process isolation Fission and is enabled by default on desktop. Fission is not yet enabled by default on Android, and when manually enabled it results in a severely degraded/broken experience. Furthermore Firefox on Android does not take advantage of Android’s isolatedProcess flag for completely confining application services. Standalone Chromium based browsers strictly isolate websites to their own process.
Source: The developer of Mull, Mulch, & DivestOS
Personally I would argue that allowing users to install extensions, mostly adblockers, you remove what’s probably the single most common real world vector for attackers, ads. So while chromium browsers may be more secure I would say you’re probably less likely to run into a problem with a firefox based browser with ublock origin on it, mobile or desktop.
Extensions are another vector. But putting that aside, because I agree ads are a much larger threat:
Cromite a Bromite fork with ad blocking and privacy enhancements; take back your browser!
Also, Mulch lets you pick your DNS provider. So even if you don’t already have system, or network, wide ad blocking, it’s not like you’re deluged in ads.
Again, I’m not saying no one should use Gecko based browsers, I’m just repeating what developers of respected hardened security ROMs have written about. Actually, that’s not true, I’m taking a softer approach as the GrapheneOS wiki/FAQ says NOT to use Gecko based browsers.