Yup, in a word, ownership.
But that's an unpopular approach these days where many companies are obsessed with minimising the bus factor to the point that their IP is as replaceable as their employees.
Companies hate ownership because it means they need to hire competent people who are more expensive
These days its turned less into bus factor and more into got-fed-up-of-wage-compression-and-left factor
Even when one is lucky to find such companies, it only lasts until the next round of layoffs or management re-structuring, been there a few times.
Also, budgets. I have been vocal about being on-call, no problem for me as long as there is extra compensation (in our org there is).
No takers yet.