Except that the 06 telephoto of the Q is constant F2.8, that I see you conveniently ignore. This means less ISO at the long tele photo and better DOF control than the P7700.
You say there’s no advantage vs the G15, but you do mention right there that the Q lens is faster anyway, so there seems to be an advantage after all.
Of course, you also have other options like a very cheap fish eye which none of the other cameras give you, custom F1.2 prime for the Q mount which none of the other options give you, or ability to use other lenses which none of the other options give you.
And still smaller than those other two you mention.
So when you say “You’d need at least two out of the three to match the capability of the G15 or P7700. Probably all 3.” you are really telling a half truth, as the other cameras cannot match either what the Q is giving you in that set.
It’s pros and cons. Oh, you also forgot the current Q auto focuses *much* faster than either of the other two options.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.