I was using .local, but it ran into too many conflicts with an mDNS service I host and vice versa. I switched to .lan, but I'm certainly not going to switch to .internal unless another conflict surfaces.
I've also developed a host-monitoring solution that uses mDNS, so I'm not about to break my own software. 😅
It's also second only to .com in terms of query volume in ICANN's Magnitude statistics with 980 mil vs .internal's 60 mil. Not sure if that makes it a de facto standard, but it's close.
The main problem I have is waking up in the middle of the night worrying that ICANN pulled some more stupid corrupt bullshit that only makes networking worse and breaks my config.
Just look elsewhere in this thread: someone thinks that using .honk as a joke is safe. But what about .horse? .baby? .barefoot? .cool? (I stopped scrolling through the list at this point but you can see how arbitrary and idiotic things have become.)
I've also used .local but .local could imply a local neighborhood. The word itself is based on "location". Maybe a campus could be .local but the smaller networks would be .internal
Or, maybe they want to not confuse it with link-local or unique local addresses. Though, maybe all .internal networks should be using local (private) addresses?