They don't use their own product, and they don't want their engineers to use their product either. They want velocity, and you can't have velocity if you're bogged down by doing end-to-end testing and finding friction and whatnot.
For many of them, the quarterly results are the product.
Thanks to Milton Friedman, far too much of the manager class now believe that the end goal of their job is to make shareholders rich, and the fact that they have to do that by making a product or providing a service is something along the lines of a necessary evil.
Say I start a firm and I want to destroy the incumbent through innovation but can’t pay a very high wage - will the best people who are needed to compete and beat said incumbent forgo a lower salary for the mission?
I don’t know. And that’s part of the problem - you can’t have your cake and eat it too.
I think that all of us have spent too long living in a time of rising inequality.
When you know that things are expensive compared to salaries, and that this is gradually getting worse, it's absolutely a natural and expected (though not universal) response to try to seek the best compensation you can obtain.
If, on the other hand, you know that your compensation will be enough to ensure you have a good, solid standard of living, both now and into the foreseeable future, because wages are high compared to cost of living and the power of labor is strong, then it's going to be much, much more common for people to be willing to take that reduced overall pay in order to do work they feel is more meaningful.