Data-only eSIM · what actually breaks
A data-only eSIM gets you online. That is not the same as getting you in. Sign-up screens ask for a phone number, and some of them will only take a local one.
Four of the ten services we checked refuse a foreign number, three need no number at all, and one taxi app will take your passport instead.
Read the Japan check →Taiwan, Thailand and India are the ones we get asked about next. Each takes a full round of checking before it goes up, so they go up one at a time.