@tulpa GeckoView (I think this is what they call it) based browsers are less popular so they are less likely to get targeted even if the design is inferior.
I also think that sandboxing as a security technique is overrated, we've seen in recent years how hardware flaws like M1racles and Spectre/Meltdown make it possible to escape the sandbox. No, it's still good, but it's not bulletproof it's often considered to be.