I'm curious if search companies ever publish information on whether their products are actually useful. For e.g. One measure of success for something like a se

I'm curious if search companies ever publish information on whether their products are actually useful. For e.g. One measure of success for something like a search engine could be a reduction in the number of different search queries leading to the same user-click. People needing to rephrase and re-search is bad for the users, but paradoxically good for Google. And so, the search product would be vastly improved if Google targeting having the least "engagement" and a higher result convergence. But then again, that applies to many advertising-funded web properties.