Its a fun thought experiment, but I think it falls down when you start to consider how many "right bets" Microsoft, Apple and Google made. The other examples are no where near as mature and, to me, are still working on their initial idea.

The 3 I mentioned I think much of their success comes from implementing their first ideas very well and attracting the excellent talent which allowed them to pivot or broaden when other things came along.

Of course that then lands you back on another familiar YC idea of investing in teams rather than ideas.