Same experience over a little bit more than a decade. Essentially none of the custom email addresses I use have started getting spam. The two cases where I did get a lot of unwanted email was when I was buying a car and looking for a mortgage. However, when I unsubscribed from the emails that was respected. Biggest source of spam in those ten years was for my personal email address, which clearly was leaked from some family member's address book—on multiple instances my address was spammed along with other people in the same social circle.