micro atx is even older.
Did ASRock had anything to do with any of the standards?
Meanwhile, any product being sold by the likes of Beelink and Minisforum is far smaller than any of those standard. The board alone is about a quarter of that area.
Why do you claim that ASRock pushes any form of boundaries in small form factor PCs?
If you think creating a new form factor that others want to standardize means pushing boundries, then no.
Beelink and Minisforum don't sell motherboards. They sell barebone PCS with soldered on CPUs. And certainly not anything in the HEDT space. So they are in a completely different category IMO.
But utilizing the existing standards of itx/mini-atx (or nearly so), ASRock is far and away a leader in this genre. They are packing so many features into these form factors that few, if any, are able or willing to replicate.
I'm not sure your opinion is well founded. Take a cursory look at Amazon,and search for mini PCs. The bulk of all the offers follow one of two form factors, ASRock is nowhere to be found.