"None of the big tech companies know what their services are actually worth to their users".

The users are the product. They sell their attention to the advertisers. And they know exactly how much that attention is worth, because they use auctions to set the price.

In other words, you agree with me that the tech companies don't know what their services are worth to users. They know what their ads are worth to advertisers, which is not the same thing.

They also basically don't care what their services are worth to users, except in the very weak sense that the services have to be sufficient to get users to use them. But that's an extremely low bar.