That sounds like a cope. I have worked with many engineers who delivered as high, or higher, quality and impact features at higher volume by working longer, because they cared more about technology and/or the product. And I've also seen the same person (myself included!) with drastically different output based mostly on time put in. The simplest case is people who have kids and now want to spend more time with them; for some people, like me, it's an interplay of hobbies and how interesting the project itself is. The productivity decreases, based mostly on time spent. Can they respect themselves more as engineers after that?

It even goes beyond the job, e.g. does one read research papers or code at home? That would usually make one a better engineer, but it's not great for work life balance.

Not a cope, genuine opinion. I have seen people who spent a lot of time in work long term and generally they were not all that productive. Meetings took longer, because their socialization needs were not met.

And when whole teams work long because management demands it, what you usually see is tired people wasting a lot of time.