I'll take the other side of all this hate. We use celery for quite a bit, and I struggle to sympathize with TFA.

Much of what's written comes back to using old python2 libraries or just complaining that celery doesn't have defaults that better suit you. The very first issue mentioned, about not manually setting the concurrency level...this is basic stuff. It always boggles my mind when people deploy something to prod with the copy/paste "get started" instructions from github. Why do people deploy critical infra layers without spending a lot of time to understand the thing they're depending on?

There are genuinely bugs in celery, and task queues are particularly hard to get right, especially with pluggable backends. But if you RTFD and follow good devops, you will have a perfectly fine time.