As discussed elsewhere in this submission, if you want real mileage by road then it’s by coach you have to go.
I used to be scared of flying (technically still am but I’ve since learned to manage that fear) so over the years I’ve travelled great distances by road and rail. I’ve used coaches a lot to travel the U.K. and Europe. 12 hours has taken me from London to Amsterdam. I’d wager another 12 hours would get you as far as Eastern European, possibly even Russia.
But such a journey would have to be pre-booked coaches. You couldn’t get there on buses.
In Europe, trains are far more comfortable, usually faster, and with better networks in most places. They are more expensive, but if you are in your early 20s (up to 25 or 27) the Interrail ticket is an all-summer (or several weeks, as you chose) pass to travel as much as you want, over most of Europe.
"Better" network is an interesting choice of words if you're listing it as a separate quality from speed. Better in what way? I doubt anywhere in Europe has a train network with denser routing or more stops than the bus system.
There are many, many cities and villages that are only accessible by regional buses. I doubt the residents would consider the train networks to be "better".
...and my perspective may be both local and outdated. Intercity coaches were actually illegal here in Germany until 5 years ago or so, intended to protect the train services (and, I guess, roads and the environment).
Interesting that the Prague journey is 7 hours less than Berlin which is closer. Is this just because the number of stops is greater on the Berlin route or something else?
It could be that Berlin is the "end" of a trip around Germany, but Prague is the beginning of a trip to Czechia/Slovakia/Hungary/wherever-it-ends-up.
I had a friend who took the bus from London to Poland after each term at university. It was about 20 hours to the first stop in Poland, then another 12 or so going around Poland until it got to his city. (This was decades ago.)
Possibly, though the location of the stops might matter more (ie the Berlin route might be a greater mileage but less direct). The change over likely doesn’t help either.
I used to be scared of flying (technically still am but I’ve since learned to manage that fear) so over the years I’ve travelled great distances by road and rail. I’ve used coaches a lot to travel the U.K. and Europe. 12 hours has taken me from London to Amsterdam. I’d wager another 12 hours would get you as far as Eastern European, possibly even Russia.
But such a journey would have to be pre-booked coaches. You couldn’t get there on buses.