It's more that they know they can eventually clone any successes the other companies have and steal their market share. Their really is no moat. In a more normal environment they would be buyout candidates but that's a bit too far gone at this point, so you just let them run until they are out of gas and Google can benefit from any advances without upfronting the cost.

Even with anthropics record breaking revenue growth I don't see how the pure AI companies can sustain, but the catch-22 is that any obvious pivot proves that. This puts the more traditional tech companies in position to ride the back of the wave until the growth curve tops.