For travel, it’s great. When I went to Germany four years ago, getting data on my phone without paying an exorbitant roaming fee involved waiting until I got to Germany, buying a SIM card at a train station, then finding WiFi access so I could complete the registration process, which involved a video call with a Deutsche Post agent to verify my passport for some reason. The last time I went a few months ago, I bought an eSIM before I left, and it activated automatically as soon as I landed in Europe.
Granted, I think a large factor in the hassle the previous time was due to German regulations involved in getting a phone number, but since I didn’t want or need a German phone number it was just unnecessary hoops to jump through. Now I can buy an eSIM from any number of countries that is valid throughout the EU with way less hassle, and I can get service from whatever provider I like rather than having to depend on whichever SIM card I happen to find at the local shop.
I’ve also never had an eSIM swap take hours to days—they’ve always been effectively instant for me. When my phone was damaged and I couldn’t get the eSIM transferred to a temporary phone while I got it repaired, I was surprised by how easy it was to generate a new eSIM online. If I had lost my phone, and I had a spare phone to use, getting service transferred with an eSIM would be a matter of minutes, rather than hours or days to get a replacement physical SIM.