Is power-demand the only reason?
Back when I owned the Revel Salon2, B&W 802D2, KEF 201/2, Linkwitz Orion 3.2.1, and Philharmonic 3, a friend who owned Magnepan speakers came over to audition my speakers.
He was most impressed with the Salon2, so he ended up buying a pair of Revel F208 towers.
Then some time after that he auditioned some bigger Magnapan speakers and felt like he just couldn't live without Magnapan.
So he sold his Revel F208, sold his older smaller Magnapan, and bought the bigger Magnapan. I don't recall the model number, but it was one of the bigger size speakers.
I've listened to a few Magnepan speakers, and I have never liked the sound of any Magnepan. They all sounded too "diffused" to me to be considered "accurate" - like I'm listening to 7Ch stereo DSP or some other DSP all the time.
But then again, some people will listen to everything in 7Ch Stereo DSP or Hall DSP or Stadium DSP.
I have not seen a Magnepan speaker measurement that I liked either. They all look bad to me.
https://www.soundandvision.com/content/magnepan-mmg-speaker-system-measurements
https://www.stereophile.com/content/magnepan-magneplanar-mg16qr-loudspeaker-measurements
https://www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-measurements
There is a speaker for everyone and everyone is different.
Some people find "accurate" speakers too boring sounding and prefer the Magnepan sound.