In my case, I think it's related to SEO.

ad income generated by traffic to page (either organic or typos) exceeds the cost of the domains. then scale to 10s of thousands.

My firstname.com domain gets renewed by a lawyer every year. Last 12 years. Through a local web host/domain registrar whose customers are mostly the people who where their customers two decade ago (because they were probably one of the 2-3 companies back then) and don't know better to move elsewhere.

He doesn't even reply to emails. Not sure he checks them. The domain is not being used for anything. Mails, forwarding, websites - nothing. Nada!

It's not even his name. Let's say the domain is "johnsonmon.com" and his name is "John Mark". I wonder whether it's for some client of theirs.

Every year it gets renewed for one year at a price that's around twice the second highest price among local registrars here (guessing based on that registrar's current renewal price).