Story is that once upon a time you could sail a ship into Mariahamn in Åland and be able to hire someone for any position from cabin boy to captain. You can't now - those skills are much more diffuse.
Same thing with steam engines. Used to be you could find a boilermaker locally, because the demand was so high. Or farriers, or wheelwrights, or any of a large number of skills related to horse transport.
Even things like home milk delivery and cloth diaper services are harder to get now than in the 1950s, because improvements in pasteurization and disposable diapers have changed the economics.
If you want a new boiler, or want to hire a sailmaker for canvas, or decide you want to keep your own horse&carriage, you'll find it's harder to do so it now than 100 years ago. Not because we've "sorta lost" those skills but because the support infrastructure has dwindled.
For example, the ship the Götheborg is a replica of an 18th-century Swedish East Indiaman. It uses linen sails instead of hemp, as the original would have, because 1) growing hemp was banned in Sweden in the 1970s, and 2) the Hungarian weaving company they were going to use for the hemp sails went out of business in 2000. The linen sails, btw, were made in the UK.
Of course, 200 years ago it would have been much easier to order hemp sails for an East Indiaman.
I'm not sure that's great evidence.
Working with a historical artifact means you have to be more careful - it's more museum curation than construction. It's also generally slower to take something apart and rebuild it than to just put it together the first time.
In my mind I (rightly or not?) consider that in a different category altogether.
Ironically, she was supposedly built to only last 25 years. That might be just an urban legend tho.
[1] https://www.newbedfordguide.com/charles-w-morgan-whaling-shi...