I think it's cool that Sony is doing this -- the more ideas, concepts and competition, the better! I'm sure there will be people that will snap this up (especially for traveling).
I do find it kind of funny, though...
Internet Reviewer: "The R5/R6 feels so good in the hand -- I can finally fit all my fingers on the grip, unlike my A7RIV."
Sony: "Let's go smaller!"
On the one hand, perhaps the industry is ultimately heading to full frame sensors in tiny mirrorless packages that will eventually replace the shrinking point-and-shoot and amateur DLSR segment. On the other hand, typical full-frame lenses might quickly become unwieldy on a tiny body. Lens size would be the barrier that would need to be addressed.
It'll be interesting to see what Canon does with the EOS M line where small bodies also have small lenses. Will it compete against tiny full-frame bodies with big lenses? Will Canon retire the M line and go the same route as Sony because tiny full-frame bodies will eventually get small-enough lenses?
Fun times...
...unless you have an M and are wishing for more lenses.