Originally Posted by Cypress

The claims are unusual to you because you don’t know much about this topic.

There’s no homework needed here. All the understanding that is needed is to know that larger volume requires less pressure to maintain the same “hardness”. You should be able to see that by pumping your 23’s up to 120 psi and comparing them to a MTB tire pumped up to 45 psi. Feels about the same. A wider rim creates more volume, hence, less pressure.