The enduringly clumsy state of e-mail.
John Gruber, reminding us that e-mail tracking pixels are still common practice, and that, since the arrival of HTML support, e-mail clients have been much like web browsers, except without the modern and sophisticated security features.
I think this really is a reminder. While Apple, Google and Mozilla have all contributed to the effort to make web browsers feel more like sentinel guardians of the user, the only companies I've seen attempting to make e-mail similarly modern, secure and serene are lesser-known ones, like Hey and ProtonMail. Their goals aren't to change the entire e-mail industry, but to wrap individual in a protective barrier, so to speak.
Otherwise, e-mail feels pretty much the way it did 20 years ago. It works and I use it, but it remains pretty clunky and archaic-feeling, so I only use it when I have to. I disable image loading by default. I only type in plain text. I barely get any unwanted messages, mainly because I spend as much time as necessary to manually unsubscribe to everything I can.
And 20 years later, its oldest, simplest-to-exploit form of user tracking is apparently still the most popular.