They've made a net loss for every year in operation - although granted that loss is shrinking.
This isn't a tech business - it's an insurance business that uses some tech.
There's no network effect, and they are operating in a price sensitive market.
Price sensitivity can be a good thing for a competitor, and tech actually does help their business (see my cousin comments in this thread).
I work in insurance tech, but not for Lemonade or anyone affiliated with them.
You expect to see it really high in the beginning (while they're learning how underwriting works), and to logarithmically decline over time, tending to plateau somewhere reasonable. That's what their loss ratio trajectory looks like, so far.