Strongly agree having worked on projects that use redux-saga. More difficult to debug, more magic, no real benefits. I would love to be proven wrong however.
How large were the projects? Was there a high level of concurrency? redux-saga is definitely an example of over-engineering unless you fully understand its benefits (which are many, depending on context).
The main project I worked on that had redux saga was a very simple concept that I think would have had no problem without it. There was no complex behavior. I think your insight about over-engineering would definitely apply here. It was apart of the basic boilerplate of the front-end from the beginning in this project despite not having a reason to use it. This seems to be a common theme based on the react developers I have been in contact with.