Later, I worked at a smaller company that let a young talent bring in a newer, more complex technology stack, made for solving problems at a scale they not only didn't have, but would never even aspire to reach. His reason was clearly that he wanted it on his resume; it took me a while to figure out that was his supervisor's reason for letting him do it. Both probably left soon after, leaving behind a higher maintenance load that would have helped them only if they reached a scale 1,000x bigger than there was any prospect of.
These two cases (and several others like them) have convinced me that it is possible to screw this up in either of two directions. No doubt there is a good rule of thumb to determine how to get it right, but I haven't found it yet. The best I know of is, to be aware that it is very possible to get this wrong in either direction.