For me the main benefit of sqlite is that it's a library rather than an app.
I've been assured by many HN users that running apps/sites on a single VPS requires near-zero maintenance or monitoring to achieve acceptable uptime 24/7/365 for years on end, sooooo...just pretend it will never fail like your main server process?
Im not saying that sqlite isn't useful, im mostly saying that using postgres doesnt have to be complicated.