It is my understanding that the fixed operating costs (hosting/bandwidth) for this site are quite low. Not sure how much staff they have, but they are doing a really good job.
[1] https://www.newyorker.com/news/letter-from-silicon-valley/th...
Which entity are you claiming is the owner and funder of HN? The FAQ says:
What's the relationship between YC and HN?
Y Combinator owns and funds HN. The HN team is editorially independent.