Part of that is getting older. A decade ago I contributed to Python under the name "Demur Rumed" & that's what they put in the 3.6 contributor list. Back then I worked at a company that didn't use GitHub so it was all personal stuff that I'd put under that name
Since then I started working in open source companies that are operating on GitHub. An early meeting someone asked "who's this Demur Rumed making random pull requests?" sheepishly I declared myself, "Please update your profile with your real name"
Growing up in the 00s, the advice for teenagers going online is that they should protect themselves by not sharing their identity. For years I avoided associating my real identity online (outside obvious things like banking, which wasn't associated with my online identity)
Hard to tell if this is a macroscopic trend, or just my experience. Personally I prefer pseudonymous identity. But I've never been anonymous, since there's 20 years of digital trash left around at this point