The case for eSIM
The main selling point is convenience. You set up a travel plan before leaving home, and you arrive connected. No hunting for a SIM kiosk in an unfamiliar airport. No standing in line for 20 minutes at a carrier shop. No passport check just to buy a data SIM.
Your home number stays active. This matters more than most people realize until they're abroad waiting for a bank 2FA code, or trying to receive a call from their hotel. With an eSIM as the data plan and your home SIM still active, both work simultaneously.
Multiple profiles on one device: you can install eSIMs for upcoming trips in advance, or switch between plans in settings without physically touching anything.
For countries where buying a local SIM is bureaucratic, eSIM is the clear winner. Japan, South Korea, and India all have varying degrees of ID registration requirements for SIM purchases. eSIM skips all of that.
The case for physical SIM
Price. In many countries, local prepaid SIMs cost almost nothing compared to international eSIM plans. A SIM in Thailand might run you 300 THB (around $8) for 30 GB. A comparable eSIM plan from an international provider could cost $20-25 for the same data. The gap narrows in more expensive markets but is significant in Southeast Asia, South Asia, and Eastern Europe.
Works on any unlocked phone. You don't need a modern device with eSIM support. Older phones, secondary devices, travel routers: physical SIM covers all of them.
Available at airports and convenience stores worldwide. For long stays in places like Vietnam, India, or Poland, local SIMs are ubiquitous and cheap.
The downsides of each
eSIM downsides: requires a compatible, unlocked device; prices are often higher than local physical SIMs; some providers have flaky apps or slow activation; if a plan fails, you can't just walk into a shop to fix it.
Physical SIM downsides: you have to find a shop, which can waste travel time; ID may be required; you lose reception on your home number while it's swapped out; the tiny card can fall out, get lost, or get damaged.
When each actually makes sense
Use eSIM for: short trips (under 10 days), countries with SIM registration requirements, when you need to stay reachable on your home number, when you're arriving late at night and don't want to deal with finding a SIM shop.
Use a physical SIM for: stays of a month or more, countries where local data is very cheap (India, Thailand, Vietnam, Poland, Ukraine), traveling with an older device that doesn't support eSIM, when you're price-sensitive and the local SIM price is substantially lower.
The honest verdict
For most travelers doing 1-2 week international trips with a modern smartphone, eSIM is worth the slight price premium. The convenience is real. The time saved at airports adds up. Keeping your home number active is genuinely useful.
For long stays, or any trip to Southeast Asia where local SIMs are extremely cheap, the math shifts. Do a quick price comparison before your trip rather than defaulting to one format.