Parking vs. blocking makes no difference to me atm

When using asynchronously running processes, i.e. with go macros or futures, blocking or parking make no difference to me atm. Atm I see no reason not to simplify things, using <!! exclusively instead of <! sometimes in a go block.

;; Control, can use multiple expressions in the go body
(def my-chan (chan))
(println 1)
(go (println 2) (println 3))
(println 4)

;; (def my-chan (chan))
(println 1)
(go (>! my-chan "Hi") (println 2))
(println 3)

;; (def my-chan (chan))
(println 1)
(go (>!! my-chan "Hi") (println 2))
(println 3)

Neither #2 and #3 never print 2. What’s the difference?

;; (def my-chan (chan))
(println 1)
(go (>!! my-chan "Hi") (println 2))
(go (>!! my-chan "Hi") (println 2))
(go (println 2))
(println 3)

;; (def my-chan (chan))
(println 1)
(go (>! my-chan "Hi") (println 2))
(go (>! my-chan "Hi") (println 2))
(go (println 2))
(println 3)

Both these sections do the same thing. From my perspective, >! performs exactly like >!!. Why complicate the asynchronous headspace with “parking” and “blocking”, when both block each’s current process?