The Hindex is a measure thats become the target. So 1 seminal paper is much much worse than 10 completely forgettable papers. It is also common to divide seminal work into smaller publishable morsels to rack up the hindex at the cost of novelty and clarity. The lack of incentive to pursue novel works, also means that most papers are incremental by design. Imo, this is the biggest waste of money at academic phd programs. However, the students need to take their career somewhere, so an uncomfortable compromise is met.
Another problem is how every conference is converging into the same impact maximizing mush without any meaningful differences between them. This has massively affected searchability, which as we know leads to even greater 'agglomeration at the top'. Having different standards for novelty, experimental rigor, math rigor, scale, technical fit and the like would allow for accepted papers to follow internally consistent searchable constraints, while the diversity of target audiences accross conferences would allow for different types of research to coexist. In my field, conferences are only differentiated by deadlines and status. Everything else is secondary.There arent too many papers. There just that the quality of curation has gone to shit.