someone already said but it's an emulator the way java vm or python vm are emulators. they emulate a computer architecture and environment that is uniform across different hardware types.
in the uxn case the different hardware types include small raspberry pis, Nintendo DS, etc. So having the baseline be really simple means knowing the code you've written for uxn will run on all these different hardware types.
You can also build a CPU that runs uxn code directly on hardware (I assume).
if you are a user then the only reason you'd run uxn on modern powerful hardware is if there is an app written for it that you wanted to use. Just like java, or python, or rust.
For a developer, grabbing uxn might be an aesthetic or political choice, like the language, or you want to target low power hardware use cases.
in the uxn case the different hardware types include small raspberry pis, Nintendo DS, etc. So having the baseline be really simple means knowing the code you've written for uxn will run on all these different hardware types.
You can also build a CPU that runs uxn code directly on hardware (I assume).
if you are a user then the only reason you'd run uxn on modern powerful hardware is if there is an app written for it that you wanted to use. Just like java, or python, or rust.
For a developer, grabbing uxn might be an aesthetic or political choice, like the language, or you want to target low power hardware use cases.