Interesting take, I think my Deck is a great size and it easily fits in my shoulder bag, I bring it everywhere. Don’t have a want for anything smaller honestly, it feels so good in my hands, anything smaller just gives me hand aches after a bit. But I can understand your perspective.
I’m a shorter dude (5’8"), so while I’m in love with my Steam Deck, it’s definitely a little much for me sometimes. Heavy to hold up, and I carry it in the OEM case. That being said, I’m a HUGE fan of the new case and basically only use the inner case, leaving the outer shell at home.
When they came out with the OLED (and the special edition) instead of giving the regular shell, it was 2 shells. 1 thinner one that’s a bit thicker than the deck, and then the big one with a handle and the elastic covering a space to carry the charger. The small one actually velcros into the big case.