From my experience with modern software and services, the actual practice of QA has plainly atrophied.

In my first gig (~30 years ago), QA could hold up a release even if our CTO and President were breathing down their necks, and every SDE bug-hunted hard throughout the programs.

Now QA (if they even exist) are forced to punt thousands of issues and live with inertial debt. Devs are hostile to QA and reject responsibility constantly.

Back to the OP, these things aren't calculable, but they'll kill businesses every time.