Wingo is Swisscom's online subsidiary and runs on the same network. Coverage and 5G quality are therefore identical. The difference is almost only price and service model: Swisscom with stores and full service, Wingo online and much cheaper.
For most people, Wingo is the rational choice: the same Swisscom network at a fraction of the price, cancellable monthly. Staying with Swisscom makes sense if you want in-store advice, Internet/TV bundles or the broadest roaming portfolio. Anyone who just wants to call and surf mainly pays for the name at Swisscom.