[Question] How many EAs failed in high risk, high reward projects?

The ideas of high risk, high reward projects, value in the tails, etc. are quite common EA positions now. People are usually reminded that they have a low probability of success and that they should expect to fail most of the time. However, most people I know/​have heard of who started ambitious EA projects are doing quite well. Examples would be SBF, Anthropic, Alvea, and many more.

My question, therefore, is: Is the risk of failure lower than we expected, or do I just not know the failures? Do I just know the selection of people who succeeded? Is it too early to tell if a project truly succeeded? If so, what are concrete examples of EAs or EA orgs not meeting high expectations despite trying really hard? Is it possible that we just underestimate how successful someone with an EA mindset and the right support can be when they try really hard?