For me, it's just nice/satisfying using a aesthetically designed piece of kit, even if not top of the line performance. Which is issue for bikes, since a well tuned bike makes a huge difference. I don't like looking at all the bits of gear drive system, I like aesthetics of single speed, but riding one PIA. Ended up with a slick belt drive + internal hub setup. Van Moof (which I was considering buying) was basically the only ebike vendor that had similar aesthetics, and cover for chain/belt drive option. Checked my aesthetic boxes enough that I was fine if performance was average because it's ebike and I won't be physically struggling if something goes out of tune anyway. Support killed it for me though, and it seems like killed the company as well.
Belt drive and gear hub is an awesome combo indeed. I'm spending a stupid amount of money to build a gravel bike with that setup, since it doesn't really exist.
I like a different aesthetic but to each their own. A bike you love is the best investment you can make.
There are some that use Shimano Alfine, like the Priority Apollo and Shand Leveret, and others that use Rohloff like MiTech R-Gravel and Shand Cycles Stooshie Rohloff. They're still much rarer that derailleur bikes, though the latest innovation is using a rear derailleur and a 2 speed gear hub with the Classified Powershift.
If you're not into bikes, try a few of them. I find any properly tuned bike to be an absolute joy to use, although I never tried a Van Moof.