It's not a major problem for many people visiting Germany since roaming charges no longer apply within EU and you can carry your operator's plan to other EU countries, which IMO eliminates the need to buy a new SIM card altogether for many people.
It only sucks if you come from somewhere else not in EU. Even then operators (iirc at least Vodafone) offer remote verification of documents over a video call, so it's not as painful as it might seem to be. I don't see how eSIM would make this easier, since the main pain point of verifying your identity will remain.
I don't think eSIM has a number, and so no verification is needed. I bought a German eSIM a month ago and it worked without any need to register. I never had to do any video call in a language I don't understand. eSIM just worked.
I just did this in Germany last week, it has gotten a lot more painful. They now want an official document showing your German address (Personalausweis or Meldebescheinigung) making it impossible for foreign visitors to get a German SIM. Two years ago it still worked with only my passport.
Next time I'll just do roaming on a prepaid card from my home country, unfortunately my current provider doesn't support roaming in Germany.
It only sucks if you come from somewhere else not in EU. Even then operators (iirc at least Vodafone) offer remote verification of documents over a video call, so it's not as painful as it might seem to be. I don't see how eSIM would make this easier, since the main pain point of verifying your identity will remain.