I'll be honest, even I do this when it's a form that has an email requirement but that I don't otherwise care about at all. I'm not gonna sign myself up for spam. Sometimes example.com and whatever other testing TLD that comes to mind is blocked because they want something that could plausibly be a real email address, so I give them something that could plausibly be a real email address, like asfgjklahsfgjklh@asdfoghuasfga.com