Nice strawman, but portability has long since been achieved.
You say you prioritize usability but then defend an idiotic and regressive design that impedes usability so disgracefully that even Apple has had to admit failure.
The trackpads are another failure, being way too big and thus suffering from spurious contacts from the heels of your hands. Why didn't Apple at least make the giant trackpads useful by having the Pencil work on them?
I'd bet that things like having or not having a car dictate a lot of our everyday carry choices - it has for me. Now I'm wondering if an iPad Mini is too small...
Of course, one is sometimes a proxy for the other, but it's not a given.
I also travel a lot, and want a thin, lightweight laptop - but it must be functional, reliable and have excellent battery life; I don't care a jot if the next generation is 1mm thinner than the last if it means sacrificing keyboard usability and reliability, battery life and cooling.
We past the point where thinness was an issue a long time ago. Now it's just a pissing contest.
I’m not defending the design, I’m defending Apple’s prioritization of portability in their laptop lineup. The fact Apple is retreating on the keyboard design is evidence enough that that particular design choice was a failure. Doesn’t mean their priorities are wrong though even if you _personally_ disagree with it.