I absolutely love the wild and crazy ideas that [never] came out of the 50s. The level of imagination and innovation, to me, is unparalleled; even today. Everybody, and their brother, were trying to pioneer this awesome and automated future, the likes of which no one (at the time) has seen.
Completely different engineering (ZT transaxles are hydrostatic), but yea, it's nuts they cost as much as a car.
Far, far less material, far less structure, no safety engineering (well, not like cars anyway), and frankly pretty low quality structural design and manufacturing. My family is always welding something back on, or replacing a part.
On one hand, having a closed driver space is pretty normal for agricultural machines nowadays. On the other hand, most people's lawns aren't even big enough to have good reason for using a ride-on mower.