I think the problem is that we've let JS engines become absurdly complex so there's no way to avoid them having really gross bugs.

That said, I think that the V8 team has done a fantastic job of securing their engine. Their heap sandbox feature is really inspiring! It's really wild that (as far as I can understand this issue) someone is able to bypass it.

(Posted from a memory safe browser - WebKit MiniBrowser compiled with Fil-C. Pretty sure this is safer than even V8 and the heap sandbox.)