Is the Golden Era of Startups Ending?

I have spent much of my career looking at startups and trying to be early at spotting transformative trends. It is clear that a huge transformative trend is now forming related to AI's Machine Learning and it is probably going to be as important as the microprocessor once was.

The big change, however, is that it looks like the three most important players will be Microsoft, Google, and Facebook. The only significant startup was Open AI, which Microsoft acquired.

This brings me to wonder if the era of world-changing start-ups has come to an end. I see a lot of evidence that this could be the case.

It seems to me that every company is now a tech company and every consumer is now a tech adopter. So the dusty old image of two kids in a garage with a dream to change the world has evolved into something less than that.

Tech innovation markets have scaled and they require huge investments of resources that startups--almost by definition--don't have.

I'm thinking of writing an ISTM piece on that. What are your thoughts?