True, but not in the way I think you might be inferring. A construction planning/quoting engineer can give incredibly well detailed and highly accurate plans and timelines for building a building, road, bridge, etc. They don't know how to make the steel, or how to weld properly, or how to mix the concrete, or how to measure slump, or a thousand other tasks the construction workers know by heart. I don't need to know exactly how my developer does XYZ, but I can have a strong enough understanding to know if it's the right approach, how long it will take, what problems to expect, how to work around them, etc. I have an on-staff developer who is brilliant, and even though I don't know SQL very well, nor the language our EMR is written in, he comes to me sometimes for technical advice because I understand what is happening internally, and even come up with ideas on how to solve problems without being able to implement the fix myself.

It requires honest appraisals of your own skills and weaknesses, which is tough. But when I give an estimate on programming projects, we hit my targets on time, on budget, because I know how to write a spec, how to manage a dev team, how to QA, and how to keep development running productively. I can code a little, but I'd be the worst coder on my team, but that's not how my time is best spent.

I have 25+ years of dev experience, and currently work as an engineering manager for teams who write code in a language I've never used (but in a domain I understand well). What do you think I'm missing?

This really calls into question your understanding of the difference between the words "what" and "how". I know and understand what a marketing intern does, but I don't know how to specifically record a TikTok that will appeal to Gen Z with an IQ below 115. And I don't care, because I can measure the performance and fire or hire the intern.