I only use Gog, and the good thing is, as you wrote, I CAN take my stuff and just leave, not that I would have any reason to at the moment.
Well, I do have other accounts like Steam and Ubisoft, but that’s only about ten games in total. Stopped buying there a long time ago when I realised I can’t backup my purchases and have to use their platforms to play.
I do miss out on many AAA titles, but seriously, they don’t appeal to me anymore. And I can wait until they drop on gog eventually.
But I don’t really see the problem in multiple accounts. If not owning is not a problem for someone why should he/she care?
https://sites.uni.edu/morgans/astro/course/TheStar.pdf
Eine Kurzgeschichte von Arthur C. Clarke. Frohe Weihnachten!