Have you ever caught a marketing or spam email sent using one of your email aliases?
That's a use case for aliases, catching if any company or service gives out your email to be abused by advertisers and whatnot. I tried looking for stories but didn't find any, I wonder if you have any to share.
Really? For me rspamd blocks at least 15 spam emails a day, usually from China or Russia. An additional 2-3 go to the junk folder, and some still slip through the cracks especially if it's coming from a gmail address.
But it could be as simple as it being because my email is publicly available (github, my website, etc.) so scrapers are picking it up.