I use a subdomain; making your main domain a catch-all will eventually result in a deluge of spam.

Instead of [everything]@example.com, I set up [everything]@yo.example.com. Discovering subdomains is much harder and the one time I encountered a form that didn't like a subdomain, I just made a forwarding address on my main domain.

Using Fastmail's rules, I have a setup where every message arriving to @yo.example.com gets shunted into a folder unless there's a different rule putting it somewhere else.