Absolutely. We burn through our scientists (and those who want to become ones) at an incredible rate.
I don't think that is the right question. Say it produces more knowledge, but the fields that are studied are selected, not by how intrinsically interesting they are, but instead by how much low-hanging fruit they have. I don't think that would necessarily be an improvement.
The upper end of mental scales, IQ or whatever, does not seem to follow the usual statistics for QA/QC of machine screw production or whatever simple industrial theory. On a purely numerical basis the world wide English Literature academic community should have maybe ten Shakespeare level professors active right now. If we do have those people, they don't have the job title "English literature professor". So where are they?
Part of the problem is "shoulders of giants". Perhaps I personally could have invented the calculus, but Newton beat me to it, so I'll never amount to much there. Under that theory unless we lose information as a culture, eventually academia will become perfectly sterile and actual advance will cease, although we can trust numerical metrics will increase forever into perpetuity as they always do unless confronted with reality, which in the case of that metric, is impossible.
There are two questions here, I think: are there a proportionately greater number of people in the world today with Shakespeare-level talent for language; and do those who exist now have the same chance of being recognized and lionized as Shakespeare did?
I don't know how we could answer the first question, but I assume it's roughly correct, just on faith in the statistical likelihood of the normal distribution of IQ/talent holding true. The second question maybe gives us some way to account for why we don't seem to see them, though. For one thing, people with that set of talents have a much wider set of fields to go into, now: in Shakespeare's time, people with literary talent could write poetry, or plays (or, as he did, both), and not much else. Today, both of those are sub-divided into lots of sub-genres, and prose fiction exists (and is also highly sub-divided), and prose non-fiction, and song-writing, and journalism, and writing for tv and movies, etc. We wouldn't expect to see every current Shakespeare working solely as a playwright: we should be looking across all the fields that need literary talent, if we want to accurately count today's Shakespeares.
And we need to consider whether a Shakespeare-level talent today has any reasonable chance of getting Shakespeare's level of recognition and admiration. There is so much more content today that any one person's output can't get nearly the attention and focus that the smaller world of Elizabethan England could give to Shakespeare. Achieving 'legendary' status probably depends less on absolute talent level than on how much one stands out from one's competitors - that's much harder to do in a larger, more sophisticated world. You would probably have to be significantly better than Shakespeare today to stand out as much as he did in his time.
Going back to the sciences, the situation is a little different because it probably is the case, as you suggested, that the field is finite and there will probably come a time when there is nothing significant for a new Newton to discover, and thereby be recognizable as a Newton-level mind. That's less the case for the arts - the working space there is much larger, possibly infinite. But the increasing sophistication and the growing number of fields to work in is the same in science as in literature, and so is the consequent dilution of attention and recognition. I'm not sure that conditions now allow us to reliably recognize our geniuses.
On why we don't have more Shakespeares alive today- what if we do? Would we revere Shakespeare as much as we do now if there were 9 others who wrote at the same time? In any case, I'm not so sure that Shakespeare would have the job title "English literature professor" either. Maybe they're TV and film script writers that we don't hear about?