If your carrier is in the European Union, roaming in France is included in your plan thanks to the "Roam Like at Home" directive. In theory, you don't need an eSIM. In practice, your carrier often applies a "fair use" policy that caps your data or throttles your speed after a few days, especially beyond 2-3 weeks. The Alosea France eSIM guarantees stable unlimited data from day one to day last, with no surprise on your bill when you get home.