Luck is a huge factor in success, and it plays into all those things in very direct ways. I've been involved in three failed startups (and one successful consultancy) and seen all those factors play out.

Timing and making a product enough people want (and are willing to pay for) are the two areas where luck plays the biggest role. Market validation is a huge issue for new technology, and it's surprisingly easy--with the best market intelligence you've got--to build something that not enough people want (yet) to make money.

And not all markets allow fast pivots or particularly small MVPs. Sometimes you don't know it isn't going to get picked up until it's too late to change course. In other cases there is simply no way to know if you should take a fairly good offer today and cash out, or not. It's easy to point to cases where founders turned down good offers and went on to make large multiples of them, and cases where founders turned down good offers and went broke.

It would be a very valuable exercise to gather up cases like that and present them in a business school context. My bet is that no one would be able to consistently make the right decision based on the information available at the time, which would make the role of luck unequivocal.

Market fit should be worked out ahead of the team by the cofounders. The great team will contribute to it and over time everything evolves. Should the market shift fruit when you have the team, team transparency will help everyone steer the ship in a different direction. Otherwise the company will run out of cash chasing the founders fixed mindset.

It was a great product, delivered on time. It fulfilled a genuine need and it did it better than anything the competition had to offer. But the market wasn't there to sustain the company, and there was no reasonable way to know that far enough in advance to do anything difference.

This is the essence of luck. People hate that, but it's the truth.

So basically to your point. Market fit is pivotal to the health of a startup.