I see Apple going to eSIM only is another way for them to tie iPhone users into its ecosystem. The eSIM transfer function between iPhone and Android is non-existence and some Canadian carriers charges fee for issuing new eSIM QR code.
If that's true, Apple would provide a function to transfer eSIM between iPhone and iPad; however, none exists as of iOS / iPadOS 18.
eSIM is a big inconvenience for users. The only positive side I can see is buying a foreign prepaid line while being outside the country.