Depending on what you mean by "Europe" (Madrid? Waldhufen? A bunch of cabins in the north of Sweden? A random beach on Rhodes?), 4G/5G coverage is pretty good. Local SIMs are usually affordable, and thanks to the EU, roaming comes with a lot of things included.

As a reference, I have a 20eur/month pay as you go plan from Free (France) that gets me unlimited 5G, calls, messages in France, and unlimited calls and messages + 30GB internet in the whole of the EU + a bunch of other countries. Cheaper, more reliable, more useful, faster.