Would you give users push notifications without asking for their email or phone number?

I kept running into this while building web products:

If I want to notify a user about something important, the usual options are email, SMS, or WhatsApp, which all require them to hand over some personal information.

Native push feels much cleaner, but for a web product it’s surprisingly annoying to implement well.

That’s what led me to build Nudgebox: a user scans a QR code, follows a channel, and the business can send notifications directly to their phone. No email or phone number exchanged.

I’m curious how other makers think about this.

Would you actually use something like this in your product? And what would you use it for?