I have an iPhone 15 and am on Vodafone. I spend A LOT of time on 2G (EDGE) which is a massive pain in the arse. This is probably because Vodafone has a strong 2G network and so preferentially connects to that rather than a weaker >=4G network.
So I found out you can disable 2G on the phone by putting it into lockdown mode.
There is no other way to do it on an iPhone. FFS its 2024 and I spend 50% of my drive to work on 2g.
Apparently you can switch 2G off on android. But not on iPhone.