The German railway network (including the high-speed part of it) has loads of issues, and it's hardly working like a dream. That said, the interconnect between large cities is pretty great when it works. For these intermediate distances (around 500 km) it's about as fast as flying would be once you factor in getting to/from the airport (vs the more central train station), being there early etc; and much faster than driving by car.
Well, yes and no. Most of it goes through the 'green heart' of the most populated area. There's mostly farms there. The route also goes mostly along existing highways and train tracks so it was just a matter of widening the infrastructure zones that were already there. Holland is very planified so usually these things are already taken into consideration. We don't build housing right besides infrastructure anymore.
However, the environmental red tape is pretty heavy these days. The whole country is at a standstill (house building, traffic, farming) due to limits of nitrogen deposits being exceeded.
So I think it was more that than actual infringements on people's living space. Some tunnels and overpasses were made, yes. Those are the ones that are falling apart already after 10 years :')
In other countries like Germany, France and Spain the high-speed network works like a dream though. Though the good stuff is all nationally focused.