It's also possible to do this on "cruise ships" that aren't "cruise ships". My wife and I toured the Dalmation coast (Croatia, Montenegro, Albania, Greece) on the https://www.yachtcharterfleet.com/luxury-charter-yacht-48957... ten years ago - a cruise, but a cruise with ~30 other people, not ~6000. It's a big difference! The ship itself was, as you say, really just the way to get there; everything happened on-shore.
Yes, smaller boats are definitely of higher appeal to me. Went on a Galapagos cruise years ago and the max amount of passengers was 83 - we had 80 on our cruise. Sadly the dynamics of that trip have changed and I don't know if I would as enthusiastically recommend it (it's become way more commercialized and you don't get to see nearly as much as we did).
The big ships have zero appeal to me.
> a cruise, but a cruise with ~30 other people, not ~6000.
This is the sort of thing that tempts me - an enchanting vision, like something out of "Death on the Nile", only minus the death. Just a small floating hotel that takes you to interesting places, not a floating amusement park combined with buffet.
