Hmmmmm…
https://soundiiz.com lets you import playlists from a url (e.g. a Spotify playlist)
You can then save it to YOUR Spotify account (it will be the same playlist, just created by you)
I tried this one:
and it worked, but Soundiiz has a free limit of 200 tracks.
So I guess it all depends on how long the playlists are, but it should be doable!