I don’t think that’s what it would look like at all. The first stages would be cheap - mostly requirements gathering and research, but a bit more focus on that. A bit more time would be spent up front, but then you’d see multiple proposals being built, from that multiple plans being built, and finally multiple implementations to choose from. You might see A/B testing of multiple implementations or even products, and then a decision on which to pursue. You could move in multiple dimensions concurrently.

I’m not sure this is agile. I’m not sure it’s a waterfall.

We’ve got bounds on our infinite typing monkeys, but they increase every day