For this example, if you built a browser in 2000 it would put you in a great position to launch android in 2008. I think this is pg’s point. You spend all this time learning the interesting bits and when an inflection comes along that makes a new product or service possible you could be the one to likely launch it
Each new bet will be expensive and depend less on technical merit than luck and having a backup so your family doesn't starve.
That’s like saying if you can dunk in 8th grade you could be the next LeBron James. A LOT more things have to fall perfectly in place at the perfect time for that end result to materialize.
This was his point. Being prepare to launch a produce when the opportunity comes.
I am talking from the perspective of the individual developer.
You don't need your impressive product to succeed to land a good career.
If Alice is doing LLM-from-scratch work today, and Bob is doing agent harness work today, Bob's project is far more likely than Alice's to become useful/popular/profitable.
But if neither project survives, in 5 years, Alice will be more employable/at a higher market rate than Bob.