It may be skill, it may be luck, or it may be both.
But consider that this outperformance & hot-hand phenomenon can be replicated even in purely random games like coin flipping.
So sometimes taking the "winners" and trying to craft narratives of why they succeeded and what you should do to replicate them is a silly game.
Replicating SOME of the behaviors of SOME winners, upon careful study of what in their process actually allows them to differentiate themselves from others is the key, and is usually a process that requires a lot more work.
The work here was that they had some sort of investment process that required time & effort evaluating projects & their prospects over long time horizons. These sorts of processes require entire investment teams and are not the sort of thing that make it into their Fortune magazine blurb or pithy twitter posts.
The process cannot be summarized in a paragraph blurb, and even if you were to read a 300 page book you may not have the man-hours, technical skills or knowledge to replicate it.