There are some very clever things you can do with them, but this really need to know all the ins and outs of it first, and by the time you've learned them you implemented a giant nightmare.
Where sagas _do_ still make sense is highly complex async workflows, including responding to dispatched actions, "background thread"-type behavior, and lots of debouncing/throttling/etc.
But yes, I've heard of plenty of cases where sagas made a codebase unreadable, and it's a shame that they get so heavily pushed by some early Redux users.
FWIW, I've actually been working on designing a new "action listener middleware" that we'd like to ship in an upcoming version of Redux Toolkit. It started off as very simple callbacks, but by adding a few key primitive functions like `take`, `condition`, and `delay` I think we've been able to to come up with something that can handle maybe 75% of what sagas can do with a much smaller API surface and bundle size. I'd love to have you or anyone else using Redux take a look and give us some feedback on the current API design and let us know if there's other use cases it ought to cover: