You are basing this on the assumption that every single carrier uses eSIM, which they do not.

The sim card has exactly nothing to do with your stored settings.

Sim card is the carrier information, all the sim card does is give you a phone number.

Phasing out sim cards is a bad idea, now your hardware is locked to your phone number.

When your phone dies you don't have the luxury to take the sim out and use another phone.

It has nothing to do with 3G and below.

I've always had a sim card because I've always been on GSM networks.

The phones without sim cards were CDMA / TDMA networks.

Regardless, I prefer having my phone number and hardware device separate.

If my phone breaks I have a spare one I can quickly switch my sim into. If the phone number is attached to the hardware I need to go to a store and buy a new phone.