And it also depends on whether they're given a timeslot for that and/or incentivized for it. Automated tests need times to maintain, especially if they're some changes on flow / specs, tests need to follow.

I scrap all incentivized metrics when working on something urgent (important and soon), which is often the case. If the metrics somehow incentivized, we'll start gaming it.

Now if a dev has part on production support and automated tests are purposed to reduce the workload for support then it has time slots for that, I bet everyone will start doing it.