It's not that simple. Conflicting studies exist.
See:
(Singapore)
(Hong Kong)
The first study indicates a 50% difference in favor of mRNA after 4 doses (though 3 dose mRNA = 4 dose inactivated virus). The second study indicates a ~10-15% difference in favor of mRNA after 3-4 doses. That difference is larger with less doses, which is also consistent with the study you linked, though that could be because of how recent the dose is, rather than how many there were.
I also don't like the propaganda being pushed by the West regarding how Chinese vaccines are "useless," but there is data suggesting less effectiveness, though the margin might be only ~10-15% judging by the Hong Kong study, which isn't a lot. The Singapore study, however, is more of a problem. With a fast moving and ever changing virus, and new vaccine boosters being pushed out regularly, it's not likely that we'll get enough data to say one way or another until the wave has already passed. This makes it easy for people to push any agenda they want.
In short, I'm cautiously optimistic about inactivated viruses, presuming they update them quickly with new strains. But mRNA technology also shouldn't be dismissed. Having access to both would be ideal, in case one technology does turn out to be better in the long run.