We contemplated something similar when planning our May 2020 Med cruise. This would likely be our only time getting to that part of Europe. The sailing was on the newly re-vamped Allure and our boys had never been on an Oasis class before. It would also be the last time all four of us would travel together.
Our itinerary had 6 ports in 7 days, and I think 3 of the 6 required long bus rides inland to reach the "destination." Aka Rome is 90 mins from the port. Each way. And many ports offered more than one "nearby" destination and it was a very long day to take an excursion that brought you everywhere while giving you a tiny bit of time in each. We figured we'd be exhausted by the end of the trip, and would need another one afterwards.
What we decided to look at was a B2B of the SAME itinerary. This way we could take our time in each port, knowing we'd be back again. So first stop in La Spezia let us go to Pisa. The second stop allowed us to explore Florence. Both are about an hour away from the port, in different directions. First stop in Naples allowed us to go to Capri and explore the Amalfi Coast, second allowed us to tour Naples. Two stops in Civitavecchia allowed us two trips into Rome; visit Vatican one day, see Colosseum another day. Walk the streets, enjoy the local food and shops, without rushing from one place to another. The stops in France and Palma de Mallorca allowed us to visit those ports on the first or second leg of the trip, depending on how tired we were. Visit one the first week, the other the second. Or do a half day excursion each time, and walk the town the rest of the day. A much more relaxed experience that let us feel like we were not missing out if we weren't on the go from arrival to all aboard, knowing we wouldn't go back in the near future.
We ended up canceling it before final payment, but when we do reschedule this cruise, we will plan the same thing.