Slack (originally an MMO), Nintendo (card games), Nokia (rubber shoes) and Netflix (DVDs over snail mail) would disagree.
"We'll gather a bunch of talented people together, figure out what this industry needs and then do that, let's hope we can do that before the money runs out" can be a viable business plan. There's no guarantee it's going to work, there's never a guarantee a plan is going to work, but it can work sometimes.
Plans are useless, but planning is essential. IIRC Nintendo had been operating for decades before they shifted to videogames. And Glitch (the MMO that gave birth to Slack) was also very much a product with a plan. Plan failed, or execution failed, or the industry shifted, or something else, or all or the above. But for sure it was not just "a bunch of talented people."
I believe NetFlix actually had a plan to stream movies from the start (hence the name) and just did the DVD shipping as a way to get started.
You’re neglecting the fact that each one of those businesses had a plan, they just pivoted to more successful plans.