That's just not correct.
Current carbon steel may be more consistent common past steel, but the best crucible steel that was pre-bessemer is better than anything with the possible exception of yasuki white #1. Nothing in the diemaking steels (O1, A2, D2) that I'm aware of is as good of a razor steel as white #1, but white #1 is too hard for most people to master, and at high hardness it is a hard sharpening blade for a carbon steel. Good W1 steel is similar to the old steels, but I'm not aware of anyone making it. Old file steel and especially carbon razor steel was a higher carbon version of what would be W1, at least W1 is the closest to those because it is the least alloyed with the common carbides.
Quite a few modern items that rely on excellent quality carbon steel have taken a step backwards (edge tools, files (especially files, old files are both harder and sharper)...) because the demand from craftsmen and machinists just isn't there for the same quality level. I've got a couple swiss NOS file sets that are from the 1910s that are completely unmatched by anything available now. They are a good example of what has happened to the purer carbon steels.