Feels like people are in two camps about the 43, either they are comparing it to a 26 or similar for primary carry, or comparing it to a J-frame for "I can't carry a bigger gun" carry. I am in the latter group. I carry a double stack 9mm 80% of the time. For the other 20%, a G43 is better than a J-frame for shootability purposes (setting aside the argument that the J-frame might actually be better than double-stack 9mms for real situations real civilians get into in real life).
If I could snap my fingers and my G43 became a Shield Plus, I'd probably do it, but I don't have any regrets over the investment in the G43 because I am not that concerned about round capacity for the "better than a J-frame" gun, and I know the G43 works and will continue working. Also, I carry mine in a G48 holster when AIWB, because more barrel length conceals better, gun is far less concealable than a G19 AIWB in a true G43 holster.
And as for the G48, I spent the first decade of my EDC life in a state with a 10 round capacity limit. The most common solutions to this are 1) carry the large handgun with neutered magazines (did this with a PPQ, PX4c for a bit), 2) size up the caliber because "if I can only have 10 shots I want them to be ten .45s" (thank you reason number 2 for my HK45 which I still love, less happy about the stainless slide USPc .45 I sold, biggest gun-selling regret so far), 3) carry a smaller gun than you would to get <=10 rounds organically (did this with a P2000sk, G26, and PPS), or 4) become a 1911 guy (missed this one somehow).
I was smart enough to realize I shoot bigger guns better than small guns, and that there wasn't really any benefit to a larger caliber, so the hunt for a full-size 9mm with standard 10 round magazines was on. And there were none. The P239 was always of interest but never got into one. The G48 would have gotten me very excited back then, because what I wanted was a size-efficient 10 round Glock 19. I don't know if this is the primary market for this gun or not, but it makes a ton of sense to me.
Now that I am free (for the moment), not so much. I shoot it worse than a 19, it holds less than a 19, it doesn't share holsters or magazines with almost anything (which is one of the best things about Glocks), and I agree, it makes no sense as an option for one who has all the choices.