The problem with those roaming SIM packages is that they're usually dramatically more expensive than just buying a local SIM. It's fine if you only travel sporadically, but if you travel often it really adds up.
Example: I have a SIM from Free (French carrier) that gives me 150GB data in France and 25GB of roaming data throughout the EU and a few other countries for €20/month. It would cost more than double that to match the allotment with the travel carriers you find on e.g. Airalo.
I think the problem is less eSim vs Sim, and more market forces. I think the hope would be that if eSims are the only option for iPhones, it'll force more and more carriers to support eSim.
Example: I have a SIM from Free (French carrier) that gives me 150GB data in France and 25GB of roaming data throughout the EU and a few other countries for €20/month. It would cost more than double that to match the allotment with the travel carriers you find on e.g. Airalo.