[mrkurt]

YC itself didn't do convertible notes — other investors did. YC's investment as far back as 2011 was an equity mechanism (which I think was similar to the new Safe).

Other seed stage investors used convertible notes. These technically "debt", but only as a mechanism to keep from having to go through valuation exercises on <3 person companies that had plenty of other things to worry about.

Debt term limits and interest rate limits were bad for companies. It was not possible to have debt with, say, a 50 year term and a 0.1% interest rate. Instead, the debts had 5 year terms and non-negligible interest rates.