People use Airalo app to buy eSIMs, wherever they travel to. One can buy eSIM even before you land in foreign lands. I don't have experience with Airalo, but many recommended that app on this site.
For instance, Eurolink eSIM card with 180 days validity can be had for 180 euros on Airalo.com. They also have re-chargeable eSIMs, just you need to top up just before it expires.
I can get a local SIM with 50GB data that is available with a 10 euro topup each month.
Don't forget the purchasing power in Europe is much lower than in the US (especially southern Europe). For this reason local carriers are a lot cheaper too.
