This reflects a trend of smaller and smaller companies using SSO, including startups that now use SSO right from the beginning because they know that certifications like SOC2 are on their roadmap and they want to get best practices in place early. In the past, it really was a 99% chance that customers wanting SSO were large companies, but that is changing.

That said, I'd say the trend is overrepresented in places like HN. It's still mostly bigger companies that want SSO, which is why SAAS cos keep using it as a pricing differentiator.