For starters, 'no advantage whatsoever' is a terrible yardstick to use. There are plenty, and I mean plenty of completely obvious advantages that males have over other males in all sports. Nobody cares about those, so one person having an advantage over another is not actually an issue that we care about, and it's not an issue that you care about either otherwise you'd be preaching how unfair it is that Ronaldo is able to compete at the same level that the fat keeper who plays for Wigan would be allowed to play at. Or how it's not fair that a younger F1 driver with statistically faster reaction times is allowed to compete with a driver 20 years his senior with statistically slower reaction times.
The issue is not that one person has an advantage at all, it's that one person has such a significant advantage that it's not considered fair. If you're still a male when you compete against a woman, then yes of course you have clear advantages relating to testosterone, bone density, strength etc. If you spend years transitioning to be a female, then no, the large gap significantly diminishes. But despite that, some people including the guy who posted the FB post making a false equivalency in an attempt to get likes, can't accept in their head that a male who has transitioned to a female, is no longer on the same level physically as the male.
The TLDR of that video is 'look, to show you how much of an advantage M->F trans people have, I'm going to demonstrate something to you that the M->F trans person probably wouldn't be able to do' before sitting back and patting himself on the back when the likes come in.