Using structured concurrency [1] as introduced in Python Trio [2] genuinely does help write much simpler concurrent code.

Also, as noted in that Simon Tatham article, Python makes choices at the language level that you have to fuss over yourself in C++. Given how different Trio is from asyncio (the async library in Python's standard library), it seems to me that making some of those basic choices wasn't actually that restrictive, so I'd guess that a lot of C++'s async complexity isn't that necessary for the problem.

[1] https://vorpus.org/blog/notes-on-structured-concurrency-or-g...

[2] https://trio.readthedocs.io/en/stable/

Languages like Swift do manage to make it much simpler. The culture guiding Rust design pretty clearly treats complexity as a goal.