That's not true. The AI industry appears to play a game of follow the leader copying other companies and major researchers. There's all kinds of good ideas we never see applied by big companies. So, it's not safe to assume they tried them all and they didn't work.

In fact, we've sometimes seen new companies show up with models based on research big companies didn't use, the new models are useful or better in some way, and people use them or big companies acquire them. I'd say that's proof big companies miss a lot of good ideas internally.