At this point I am operating on the assumption that ALL businesses that have my data are going to inadvertently leak it at some point, and thus I am attemtping to provide individual companies with as little information about me as possible. The toughest ones here are my online banking and my online health portal, but other than that, I have gotten pretty picky about what information I give any company.
I have an email address that I've only ever used as my AWS account email since many years ago. Somehow I started getting spam on it last year. It is not an address anyone could guess or somehow generate based on other data points such as name or otherwise.
Many of us who operate our own mail services use a unique email address for every web service we use. You'd be surprised how many of these unique email addresses I've received spam at (and have subsequently blackholed). I would estimate less than 50% of the associated services ever report a data breach event. I figure either there has been an unreported breach or, possibly more likely, the service sold their userlist either directly to spammers or sold it to another group who was themselves breached. The upside, though, is that blackholing an address used for a single service is super simple and satisfying.