A lot of work in programming languages over the past decade has been devoted to providing a safety net and guard rails for avoiding the pitfalls of thread-based concurrency. See in particular Rust and Go. It's still quite possible to corrupt data and get deadlocks, but our languages have come a long way to making it harder.

But the point of this article is to say if we ditch the notion of threads entirely and go with this other thing, we won't need safety nets anymore because it will be impossible to deadlock and corrupt data (as opposed to less likely).