I've been thinking about Flask and Quart pretty much interchangeably for awhile now and use Quart for Python backends. For those who aren't aware Quart is the async Flask and they share system internals, it is usually easy to use something created for Flask for Quart.
And most apps don't need crazy scale, they need simplicity.
Assuming that non-blocking sockets require a special language syntax that breaks seamless compositionality of functions is a lack of fundamental knowledge. No wonder you refer to the industry adoption (crowd opinion) in your next sentence, instead of applying the first-principles analysis. In 2025, the expectation is that you should've at least tried learning how Project Loom is implemented, before venturing bold opinions on the async keyword in Python: https://openjdk.org/projects/loom/
> The only way to scale a flask API is to use gevent, which is just problems waiting to happen.
This is FUD.