Totally agree that version 2 is really painful, and more painful the more we cut corners on version 1. But I've seen sooo many startups ship version 1 and sink

Totally agree that version 2 is really painful, and more painful the more we cut corners on version 1. But I've seen sooo many startups ship version 1 and sink without trace. I'd say the vast majority of startups don't ever need to worry about version 2 because version 1 isn't going to get any traction. The thing about YAGNI isn't technical - it's commercial. Ship version 1 as cheaply and quickly as possible so you understand whether there's any point in continuing.