The instinct to hunt for Wi-Fi everywhere is understandable - it's free. But hotel Wi-Fi is often overcrowded and slow, café Wi-Fi requires buying something and then asking for the password, and public Wi-Fi has real security considerations. At some point, the friction isn't worth it.
Here's a practical framework for deciding which to use when.
Use Wi-Fi for
Heavy data tasks: streaming video, downloading podcast episodes, uploading large photos, backing up to cloud storage. These are the data-hungry activities that will eat through a mobile plan quickly. Do them on hotel or apartment Wi-Fi.
Software updates. App updates and OS updates should never happen on mobile data. Set your phone to update only on Wi-Fi (App Store settings on iPhone, Play Store network preferences on Android).
Video calls from a fixed location. If you're doing a long WhatsApp video call from your hotel room, use the hotel's Wi-Fi. The call quality will probably be similar or better, and you save your data allowance for when you actually need mobility.
Use mobile data (eSIM) for
Navigation. You're moving - that's when Wi-Fi isn't available anyway. Google Maps navigation uses very little data (5-10MB/hour for active navigation; less with offline maps downloaded). This is exactly what mobile data is for.
Anything sensitive: banking, logging into accounts, anything where you wouldn't want traffic intercepted. Public Wi-Fi - airports, cafés, hotel lobbies - is shared infrastructure. Mobile data is encrypted from your device to the network tower. Much harder to intercept.
Real-time needs: checking a restaurant booking, pulling up a boarding pass, translating something on a menu. These are the moments where you need data immediately and won't wait to find Wi-Fi.
The security case for mobile data
Public Wi-Fi isn't evil and most connections are fine. But it is a shared network where the security is controlled by whoever set it up, not you. A VPN helps (ProtonVPN free tier is adequate). For anything that doesn't need mobility, your hotel room's Wi-Fi is meaningfully more private than the café downstairs.
If you don't use a VPN on public networks, be extra cautious about what you log into. Checking Maps: fine. Checking your bank account on the airport free Wi-Fi: not ideal.
The practical balance
A 5GB eSIM plan used strategically - navigation, real-time tasks, sensitive browsing - can last two weeks comfortably if you use hotel/apartment Wi-Fi for heavy tasks. The same 5GB plan used carelessly - streaming, auto-updates, constant Instagram video - is gone in four or five days.
The goal isn't to avoid spending data. It's to spend it on the things only mobile data can do: keeping you connected when you're moving through an unfamiliar place.