How had I never used cakepay.com before?

Create an invoice for the gift certificate you need of the amount necessary.

Pay it with monero.

Receive gift certificate to Simplelogin alias.

Spend at your favorite store.

The whole process took 10 minutes (3? confs before they send the gift cert).

I probably wouldn't do it for daily stuff

but for those times you REALLY want to spend your XMR or BTC at some fiat-only merchant 👍