Actually existing and having to exist are two different things.
Mo ascended to Heaven at the Far Temple said to be Dome of the Rock — which did not exist at the time but was created much later as a tourist attraction by the caliph of the time (who had moved his court from Amman to Jerusalem on a whim) to keep his restless court from getting out of hand.
During the time of mo (if he existed as a real person or not) he was said to have many ermines and he was being pursued by assassins. The question is why would he have travailed through very dangerous territory to some forsaken village months away from Mecca?
The whole bit was simply invented to create more similarities to Christ. Of course, Christ unlike mo did not personally behead 400 people ... That alone should be enough of a clue.
Mo rode to hell on a dream horse called “Barrack”. Kind of like how the current Barrack is taking us. (Which leads me to say “Scr*w you Mo and the horse you rode in on!”)