I haven't used an airbrush since my old Badger, bought about 50 years ago, bit the dust, and it was the ultra-cheap bottle type, not gravity feed, which hooked up to a can of compressed air. Only good for spraying large swaths of paint, and even doing that poorly. But I've been looking around, and I'm seeing the portable ones becoming more popular.
They're not as good as a regular one yet, but as with many things in this world, they are getting better, and will no doubt continue to do so. And I firmly believe that in a few years large compressers will be up for sale on ebay or similar sites, as people transition.
Here's one video I watched today that shows the present state of the art, and I was impressed:
Autolock Portable Airbrushed-note - fixed the URL - frank3K