Those sound good on paper but then reality hits you. Last summer we as a family decided to take a night train to reach our vacation destination.
What should have been 6-7 hour car drive was ~12 hour train ride. Sleep was not great, getting to and out of train stations, herding two small kids etc so at the time we've reached our destination we were pretty tired. Much more tired if we just drove.
The route back is where things went south. One of the beds in our cabin fell apart. Then there was some sort of the outage en route back so the train had to skip our station and we landed almost 150km away from our home.
Train company was trying to get us on the bus or train to get us back home but there were no free seats so it looked like we were to spend a night there. In the we've decided to take cab back home. We should have been back home ~10 in the morning. When we got home it was close to 6pm.
On top of that bathrooms were super dirty and there was no running water in the sinks.
We've paid ~700 euros for both ways and additional ~150 euros for the cab. If we just drove the whole round-trip would have cost us under 100 euros including lunch on our way there and back.
I just don't see this as an alternative to driving or flying in Europe — they are too expensive and the level of comfort they offer for the price is just horrible. Even if everything went according to the plan and our route back was without any hiccups driving would have been much more convenient.