The whole async ecosystem in Python seems like a bordering-on-insane duplication of work, given that a huge amount of the benefits can be gained simply by running your application under gevent (which is what many in the WSGI server crowd have been doing for yonks). The fact that every piece of code has to be rewritten (and usually in a very stupid way, like putting 'async' and 'await' in the right spots and otherwise leaving things alone) is just madness.

I'll grant you that aiohttp has a much nicer interface for websockets than I've seen in gevent-based libraries, but that seems like a very small win compared to the huge downside of chucking out most of the web server ecosystem and starting again.