It can very much depend on your domain. In the early 2000s I ran a domain for a firm and the domain had 'UT' in it. Well spammers thought it was related to university of Texas at some point and we went from around 10 messages a day to over quarter of a million. The immediate issue I has was poor back scatter protection so I had to configure that in a few days. That stopped 99.99% of the spam, but still caused massive issues with the mailboxes that did exist getting hundreds of messages per day even though we were blocking tens of thousands of mails per valid email addresses.

Spammers are miserable, I don't fault anyone for giving up.