While I'm a Firefox user, that's actually evidence to xtalh's point: that bug by itself is useless, because Chrome's sandbox meant that taking over the rendering process is not enough. They only managed to escape on Windows 7, thanks to another bug (in Windows itself - CVE-2019-0808).
Note that Firefox has a sandbox too (in fact, it shares a good bit of code with that of Chrome), and therefore a sandbox escape is necessary to elevate privileges.
(NB: I have no knowledge of the details of this specific bug.)
Leaving aside whether it makes sense to call something "useless" that was actually used in the wild, the original article specifically mentions (twice) that the Firefox RCE 0-day was also sandboxed and also only managed to escape thanks to another 0-day.
