There are professors at top institutions that publish more than a paper per week. Obviously they are not contributing with much more than just stamping their name as last authors. Least to say, this is completely ridiculous.
This is purely by convention.
A tool which was used to resolve issues among chemists and biologists is now running rampant over fields which do not have a high volume of citations. Mathematics is suffering, for example.
An Annals of Math paper might have fewer citations than a paper in Journal of Applied Statistics. But the prestige is incomparable.
The worst thing to have is indicator counting of any kind. The system will be swamped with mediocre, sometimes almost fraudulent scientists who game it. (It's just too easy to game the system: Just find a bunch of friends who put their names on your papers, and you do the same with their papers, and you've multiplied your "results".)
H-Index is also flawed. In my area in the humanities papers and books are often quoted everywhere because they are so bad. I know scholars who have made a career by publishing outrageous and needlessly polemic books and articles. Everybody will jump on the low-hanging fruit, rightly criticize this work, the original authors get plenty of opportunities to publish defences, and then they get their tenure. Publishers like Oxford UP know what sells and are actively looking for crap like that.
(My name moved from the end of the alphabet to the middle when I married. I was amused that it actually makes a difference).
part of this is contingent upon citation formats used in different kinds of publications (and thus different fields) where long lists of authors are condensed to one two or three at most.
this is not even getting into more locally scoped, second order inputs such as any given department's traditional handling of advisor vs. grad student power dynamics.
Yeah... maybe if you were on a meth IV drip and lived for 200 years...
Another point is that to get to this volume the "researcher" probably have many papers that he/she had no part in. Not even formulating the problem. In the case of physicians I encountered senior doctors who just conditioned using the department's medical statistics on adding him/her as author. That is, every paper that uses this specific public medical data adss this author regardless of their contribution... (To be clear they not even necessarily have anything to do with the data collection beyond what they already are obligated to do at the hospit, just happen to be responsible on managing access it)
Quite common in Biology and Chemistry.
Less common in theoretical physics.