That isn't right.
The truth is somewhere in the middle: definitely, you see some large companies invest heavily but (more commonly) you see small firms nibble at the edges of an existing product until it is too late for the larger companies.
Saying that monopoly produces innovation is like saying government produces innovation. It happens but given a long enough period all things happen. The question is about incentives: the incentives to innovate within large companies are terrible, that is why it doesn't happen most of the time.
Also, consolidation has happened in all industries at all times. It is a function of things that repeat: knowledge curves, lindy effects, etc.
Just generally: be wary of Thiel and his ilk. They have a predilection for ahistorical nonsense. The history in this area, broadly business history, is particularly difficult and not well known (the only tech person who I have seen get close is Patrick Collison..and then...not really).