Roaming passes are designed to look cheap per day. Multiply them by a real trip and the picture changes.
The four ways to get data abroad
Pay-as-you-go roaming (charged per MB, by far the most expensive), daily roaming passes (typically a few euros to over ten euros a day), roam-like-at-home (EU and EEA only, with fair-use limits) and a travel eSIM (a one-off price for a data bundle).
Two weeks in the United States
UK carrier daily pass: 14 × £7.50 = £105. EU carrier daily pass: 14 × €7.99 = €111.86. Roambee 10 GB / 30 days: €28.90. Same phone, partner networks AT&T and T-Mobile, about a quarter of the price.
Two weeks in Thailand
Many Western carriers charge €7–12 a day in Southeast Asia, or exclude it from their passes. Roambee 10 GB / 30 days: €17.90 — and the hotspot is included.
When roaming still wins
Short EU-to-EU trips if you live in the EU or EEA: roam-like-at-home costs nothing extra. One-day trips anywhere, where a single daily pass can cost less than a 1 GB plan. If you need your number for incoming calls, keep the home SIM on and just turn its data off.