Odds are you have 100 DAUs and your "end state" is an "our incredible journey" blog post. I understand that people want to pad their resume with buzzwords on the way, but I don't accept making a virtue out of it.

Exactly. Don't start with k8s unless you're already comfortable troubleshooting it at 3am half asleep. Start with one of the things you're comfortable with. Among these things, apply YAGNI liberally, only making certain that you're not going to paint yourself into a corner.

Then, if and when you've become so large that the previous thing has become painful and k8s started looking like a really right tool for the job, allocate time and resources, plan a transition, implement it smoothly. If you have grown to such a size, you must have had a few such transitions in your architecture and infrastructure already, and learned to handle them.