The right way to solve this is that Visa and Master Card need to develop a standard to make super easy to generate a unique payment number everytime you make an online purchase. Then that should be built in as a browser extension or component. So I browse to a site, click to pay with my Visa card, and Visa automatically generates a unique code for that site and fills it in on the form.

Blur[0] from Abine has this in their premium version. I have used it, and overall it worked well, but I had some password syncing issues and stopped using it.

A final key innovation would be if email providers would make it super-easy to generate aliases per site. I do this myself manually with fastmail, but if there was a simple browser extension that would automatically create an alias and fill in a form, that would be great, because I could have a unique address that all funnels into one place, for everything I sign up to.

Something like this can be done on FastMail using a catchall alias[1], but it requires a custom domain, and the domain could be used to link all the accounts to you.

I'm experimenting with it, but what happens when I forget a password and the email I used to sign up for it? A password manager is an option for that, but they have their own problems.

Edit: FastMail also has subdomain addressing[2]. I believe it works with all of the FastMail provided domains.

[0] https://www.abine.com/index.html [1] https://www.fastmail.com/help/receive/alias-catchall.html [2] https://www.fastmail.com/help/receive/addressing.html