I let Medium add the feature to my articles because, well, why not?!

I didn't expect any tips to actually show up, because as you and commenters here noted, people don't tip writers these days, and when the articles are behind a paywall, there's even less of an expectation anyone would pay more than that.

Imagine my shock when I got a $5 tip!

Turned out it was from a Medium writer who had made $20 on Medium, and decided he'd rather pay that forward to four other writers whose writing he appreciates, which included moi.

Ya never know!