There is quite a bit of overcomplication in that answer, because it's trying to cover all possible task kinds. In C#, compared to Go at least (but I suspect Erlang as well), Tasks are much more complex than goroutines and can accomplish more things.
In particular, C# is not limited to a single scheduler for tasks, and not all task schedulers/runners are multithreaded. When you want to interact with the UI for example, which is single-threaded, you can still use async/await to do so, but the tasks that it produces are also going to run on the UI single-threaded executor. This is very useful for avoiding the need of synchronization, but it can easily introduce deadlocks if you're writing code as if tasks can run in parallel (they are only guaranteed to wait in parallel).
If, on the other hand, you're working with Tasks that are simply used for concurrency, as in Go (and Erlang?), then those run on a thread-pool executor and you can easily and safely use Task.Wait and get sync-like code, including exception propagation, across the sync/async boundary (though you do have to handle the AggregateException, since Task.Wait doesn't know whether it's waiting for a single task or a set of tasks).
In fact, this is actually easier than in Go, since the Task that you want to synchronously wait for doesn't have to cooperate with you in any way - Tasks are objects in C# and you can observe their state directly, unlike goroutines.
The main thing I dislike about this in C# is that they desicded to have a single Task type, regardless of the executor, so the language wont help you avoid synchronous waits on the dangerous tasks unfortunately.
