Banking and account checks
Signing in from an unfamiliar country often triggers extra verification or an outright block. Connecting through a location in your home country keeps your traffic looking familiar to those systems.
Hotel networks are not your friend
Hotel Wi-Fi is often poorly maintained and frequently injects its own content. The tunnel takes that ability away.
Roaming and tethering
IKEv2 on iOS reconnects quickly when you hop between hotel Wi-Fi, a phone hotspot and cellular data, so you are not left unprotected mid-switch.