Personally I never accept the "this is optional" argument. Apple is (was?) about functional minimalism. Get rid of unnecessary. They were the first to ditch HDDs, DVDs, USB-A ports...
Adding another button, clearly not optimally implemented, which some people "might" use, seems like something Samsung or Xiaomi would do.
Sorry, but yours is wrong-headed thinking:
• There [obviously] is no
"some people "might" use." Some of us
do use it, as anyone can easily see by reading this thread.
• You need to better understand
optional, which in the case of the camera button means in addition to and/or instead of other choices. And I expect that many will use some combination of camera button and display-interaction choices.
• Look at Nikon's top camera, the Z9, evolved for 70+ years to what is arguably the best camera UI ever. Far more buttons than on Nikon's low end. Ideal camera UI is
not "about functional minimalism."
• Saying
"...clearly not optimally implemented" suggests that we should expect v1 or v2 or whatever to be
"optimally implemented,' which is
not logical IMO. E.g. Nikon spent 70+ years getting to the Z9 UI, and it is still evolving. The iPhone's camera button has only been in users' hands for a few weeks now.
• Some folks may choose to continue shooting with the
awful technique that existing display-only photography engenders, then whine here when their captures are "overprocessed." However I recommend that photogs embrace the new camera button and use it as a component of improving their capture technique.
• Folks desiring "functional minimalism" can easily ignore the [very unobtrusive] new camera button and stick with the older [IMO terrible] UI.
Just my $0.02. YMMV.