I don't think the takeaway is that innovation will slow down. The point of the article is that the large, powerful companies that we have now are on top of the game, understand technology, networking, internet, and there's no big new shift where they'll lose to startups.

Innovation will continue and Alphabet and Amazon etc. will remain dominant and powerful, controlling and doing much of the innovation.

Startups had whole new markets to enter in the past where big corporations were not prepared to go. Now, any potential new markets aren't wide open for small startups and the big corporations are ready to jump in and dominate. It's not the same.

End of widespread startup success ≠ end of innovation (but it will mean some types of innovation are stifled or don't happen)