I don't think this forum has significant costs of running, especially considering it is not in development.

They switched the backend to Common Lisp in 2019, and at the time had two seperate Arc-to-JS compilers in development. [0]

The site may feel less changeable than many, but I would be very surprised if it is not "in-development".

[0] https://news.ycombinator.com/item?id=21550123

It employs two full–time moderators.