Most providers let you run a catch-all adress on your own domain. You usually set it up with just a check-box "catch-all" and where to send all mail, or you write the username as "*" in an alias.
Not GP either, but this. To name a specific provider, I use improvmx.com. They have a generous free tier, I eventually switched to some low paid tier. Not affiliated, happy user.
I've caught a couple of hacked or sold email lists, but nothing that drastic yet.
One organization posted the email address I gave them on a public contact list webpage, so I get spam/phishing at that one.
Using a catch-all is the easiest way to do this, and I highly recommend it for other people.