I'm not sure why this is getting downvotes. I think some folks try to leverage this tool because they think it's "more performant" or "an optimization" or whatever and the result is some questionable threading code.

Concurrent programming is hard and complicated, even in languages with superior safety guarantees, especially for non-trivial, non-toy implementations. The harder it is to implement a solution, the more care and consideration for whether it's necessary or some less difficult or complex solution might suffice instead, in my opinion.