[dcldcl]

Do you encounter a lot of frustrated/unhappy older engineers?

It's worth analyzing why they plateaued (or why do you think they have).

If they gave up on learning, well that's a sad, but good explanation.

If they found themselves satisfied with what they were doing, that's not necessarily right or wrong.

Do you believe they were in an environment where they are well supported and well managed?

Moving to product is worth thinking about; but it's not a silver bullet either.

While you can pick up experience in tasks not typically done in engineering, the things that can limit a person's career is partially independent of their work experience (in terms of the task they are actually supposed to do).