I do mostly agree with you that Steam is better as a storefront than all other ones out there, but in my opinion the Battle.net launcher is still my favorite game launcher edging out Steam because of how snappy it is.
Steam just sometimes feels really slow when launching for the first time or when switching tabs/pages (I do also have it just sometimes be just a black windows, but I haven't figured out the cause yet but it is the only window that does it, so...). In comparison B.net just feels decently snappy.
They are both effectively using CEF for their launcher, but since Steam starts so slow for me I always keep it in the background and its WebHelper taking up 414MB (rn, but its always in that ballpark) is not helping its case.
People favored Google as much as possible in the '00s and then they turned evil.
For games, I favor Good Old Games rather than Steam as much as possible and go out of my way to wait for releases on their platform. Whatever becomes of them, at least I'll have my downloaded DRM-free version of my purchases.
Much to my surprise (and granted, I have the means to do so) I will favor steam whenever possible, itβs just significantly better.