Twitter has intellectual opinion

Google has smart home control and internet search (and increasingly login) and reviews

Facebook has friend and family network and market place

Uber has ride share

Air bnb has accommodation

But loyalty programs and online ordering are typically bespoke apps or cookies that store your details.

Companies don't want to give Google their data for competition reasons, so have an incentive to avoid data collection. A nostr login would also give a company access to users social media feed, allowing them to analyse publicly shared data to aid market research. Users would benefit from single login and maximising loyalty program participation. Providing user details can be secured properly, this could be a good way to get people onto the nostr protocol