Personally I think the bigger issue is variety. It would be a boring old world if we all imitated the same half dozen singers, be they source singers or revivalists.

Terrier is spot on re certain styles evolving to meet certain situations such as lack of electrical amplification. Recordings of the early 19th century mostly are of singers with high register and piercing voices for that very reason.

I tend to sing something like my own grandparents/parents and the singers I recorded in the 60s and possibly the Watersons who were a big influence on me but at least all of these are from my own region.
However, I have no objection to singers developing their own distinct style in order to be different. I'd rather this happen than they slavishly copy the style of say Martin C.