The thing that frustrates me about the idea of optimizing for engagement, is that the winning strategy seems to be to make the interface worse. If it's hard to

The thing that frustrates me about the idea of optimizing for engagement, is that the winning strategy seems to be to make the interface worse. If it's hard to navigate and find things, then people spend more time using the product. I assume that web developers have some techniques to determine whether people are spending more time on the site because it's legitimately useful and they're getting a lot of value out of it versus blundering around and not finding what they're looking for, but the whole idea of "engagement" seems like it could be summed up as "we don't think the distinction between those two things is important".