I don't know if something has changed since then, but in 2023 the author did quit their job to start working on the search engine full time [0]. So yes, it's a passion project, but it's also not just a side project.
That's really cool, although I'm curious about their plans to monetize the site, if any.
According to the creator, $200/month will maintain operations. He doesn’t mention plans to monetize.
The plan as much as there is one is to have very little costs, provide outsized value and somehow scrape by on grants, public donations. I'm currently set for about 1-2 more years of full time work (had 6 months' funds + a 1 year grant when I left my job 18 months ago).
I simply LOVE and LOVE and LOVE marginalia.
Keep rocking mate