Fast iteration can make up for a lot; it’s usually ok to be wrong if you iterate quickly. Plans should be measured in decades, execution should be measured in weeks.
The trouble with exponential growth is that the curve feels flat in the beginning. It isn't; it's still a wonderful exponential curve. But we can't grasp that intuitively, so we underrate exponential growth in its early stages.
People dramatically under estimate how many decisions one has to make before shipping the v1 of even the simplest product. They all seem obvious in retrospect, but so, so much thinking had to happen to ship something like "press a button, get a ride."
Lesson #1: Great Products Expand Markets Taylor Swift moved to Nashville at 13 and went door-to-door to record labels. They all turned her down. Labels saw country music on the decline with young listeners, and didn't see a market for a teen country artist.