My email address has been on my public website for at least 15 years, and my spam level is constant and manageable. That may simply indicate that I’m not popular enough to encounter the problem, of course.
Same for me - I do get spam, and it's frustrating, but the level seems to be broadly constant over time. I wonder if it's deliberate co-operation between scammers and other spam senders, perhaps in order to keep the total amount of spam just under the threshold that would cause people to actually crack down on the issue. Certainly, receiving only single-digit numbers of spam emails each day keeps it just slightly away from being my personal number one priority to get some proper filters installed.