Really you can. You look at the engineers who create steaming piles, and you look at the ones who don't. Over a year or two, the difference is easy to spot. For people who care to spot it.

If there's no competent front-line technical management who can successfully make this simple comparison, then, sure, in that case the team may be fucked.

It's easy to gloss over this assessment but ultimately this needs to be a key decision point for where you choose to work. No matter how well you manage complexity as an IC or a lower tier leader, if your upper tier of leaders don't value it, it won't last. Simplicity IME is not a "tail that wags the dog" concept. It's too easy to stomp out if nobody in power cares.

Yes, I should have added "...this way" because I meant that to address GP's claim of the metric-based numerical measurement.

In general, I agree that you can and should judge (not necessarily measure) thing like simplicity and good design. The problem is that business does want the "increased this by 80%, decreased that by 27%" stuff and simplicity does not yield itself to this approach.

I think this is often true and it's the limiting factor that prevents complexity from spiraling out of control. But there's also a certain type of engineer who generates Rube Goldberg code that actually works, not robustly, but well enough. A mad genius high on intelligence and low on wisdom, let's say. This is who can spin complexity into self reward.