The point isn't that Firefox is less exploitable it's that it has less blatant tracking than alternatives like Chrome. If you're an activist I'd imagine that exploits are a scary thought but the more direct threat is the tracking we (un)knowingly succumb to every day.
Isn't it the software which is tracking you? You can switch off the cellular connection whenever you need to not be tracked by the towers (if you trust your software, or with a hardware switch on some phones).
See, again: this is how message board logic turns these kinds of guides into LARPs. "Turn off your cellular connection whenever you need to not be tracked. Also use ProtonVPN."
