Would both help solve the replication crisis, and resolve this problem.
Of course then you might have 10 000 studies replicating the same easy to do study... which is why the "score" should be reduced based on how many other times that study has been replicated.
An insightful study that's replicable (but has not yet been) is valuable. A lousy study that's been replicated five times (not because it's interesting, but because it was easy to do, and the replicators knew that they'd be rewarded for replicating anything) is not valuable.
A metric that says "number of studies" is IMHO even more arbitrary, more gameable, and more detached from actual value than citation count - which does have some notion that your study actually matters to other poeple; that it was worth writing that paper because someone read it.
Or, I dunno, paleontology or sociology or other stuff.
Citations can be a useful metric here, particularly if you can identify citations of people actually using the method (as opposed to people just mentioning it in passing, or other methodological researchers comparing their own methods to it).