Even beyond some imagined nostalgia for a bygone era that probably never was, there seems to be much to love about these pioneering machines in spite of – and perhaps because of – their quirkiness and extreme limitations.
It gets a bit monotonous. Other systems are interesting because they do things quite differently from how Unix and Windows do them. To give an example, look at something like IBM's mainframe operating system MVS (nowadays known as z/OS). It is a really different world from Unix-likes and Windows. You can download the late 1970s vintage MVS 3.8J for free, run it under an emulator, and experience it for yourself [0]. (Contemporary versions are somewhat less of an alien world, given they've added stuff like a Unix compatibility subsystem, Java, and now in the most recent version even the ability to run Linux Docker containers.)
[0] I even put it in a Docker container: https://hub.docker.com/r/skissane/mvs38j
Still there are resource constraints you have to account for when you're using these things, plus getting them to interface with modern infrastructure and devices is its own challenge. Maintenance and refurbishment is also a factor, since components fail no matter how lovingly cared for the machine has been in its life.
All in all, it's not precisely a better or worse experience than you remember, just a somewhat different experience.