According to the work of (D. Harpke & al., "Phylogeny, karyotype evolution and taxonomy of Crocus ser. Verni (Iridaceae)", Plant Systematics and Evolution, Jan 2015, 301 (1): 309-325) it is suggested: "For the taxon traditionally known as C. vernus, the analyses suggest that it should be split into five species: C. heuffelianus, C. neapolitanus, C. neglectus sp. nov., C. siculus and C. vernus."

Please note that according to this new taxonomy, C. vernus (s. str.) corresponds to the previous taxon C. albiflorus.

It seems that many plants previously identified as C. vernus are escaped garden plants.

See also: https://www.inaturalist.org/flags/485558

That was intentional. Most of the plants identified as C .vernus are garden forms. With an atlas these would be mixed with the correctly identified crocuses.

I did not look at most of the C. vernus, but at a random selection as a sample.
Today I tried to (re-)identify Crocus vernus from the Alps where Crocus vernus s.str. is quite common . About 10-20% of the observations were possibly or probably C. vernus s.str. Again, most of them were not C. vernus, but more likely garden plants.
The other 4 species of the complex have been in iNat for a while. If someone had identified these species, they could have selected them.
Sometimes there is no good solution, but only the best one.

The discussion about C. vernus / C. albiflorus has been going on for quite a long time. I wanted to bring it to a conclusion now. I'm sorry if it doesn't suit everyone. I had shown the split to loarie before.