Travel eSIM or a local SIM card?
Roaming is not the only alternative. Plenty of travellers buy a local prepaid SIM on arrival, and for some trips that is still the better call. Here is the actual trade.
Where a local SIM wins
Price per gigabyte, usually by a clear margin. A domestic prepaid deal is priced for residents, not for visitors, and for a long stay in one country the difference adds up. You also get a local phone number, which matters more than people expect: some delivery apps, ride-hailing services and bank verifications in the country will only send codes to a local number. If you are staying for months, or you need a number people there can call, a local SIM is the honest answer.
What it costs you that the price does not show
Time, and often paperwork. In a large and growing number of countries prepaid SIMs are registered to an identity document, which means a counter, a queue and your passport rather than a rack by the exit. Airport kiosks that skip the queue charge a premium for doing so. And you land with no connection at all — so the maps, the ride to the hotel and the message saying you arrived all wait until the SIM is sorted.
The tray problem
A physical SIM has to go somewhere. On a single-SIM phone that means taking out your own card and carrying it loose for the trip, which is how people lose them — and while it is out, your own number is unreachable. An eSIM does not touch the tray: your usual SIM stays in, your number keeps working for calls and bank codes, and the travel data runs alongside it.
Where an eSIM wins
You arrive already connected, having paid a price you saw beforehand, with no shop, no queue and no document check. It is bought and installed at home on Wi-Fi. It costs you no time on the ground, which on a short trip is the expensive resource. And crossing a border does not restart the whole exercise — one regional pack keeps working where a local SIM stops at the frontier.
A rough rule
One country, more than about a month, and you need a local number: buy a local SIM once you have landed and settled. Anything shorter, anything crossing borders, or any trip where the first evening matters: install an eSIM before you fly. For a long stay there is also no reason to choose — an eSIM covers the first days while you sort out a local SIM at your own pace.