The housing market has a lot to do with it. In Canada, average home prices (all types) are up ~6x since 2000, and in specific cities like Vancouver and Toronto, even more so. Compensation has not kept pace. Back when I was a high school student, I didn't think pay was very important. Now I realize it's much easier to pursue one's curiosity if one can afford, say, a garage.

What does it matter if it's in the 85th percentile if they can get more money in another industry?

The question isn't, "can you survive as an EE?" sure, you can survive as fry cook at a fast food chain. The question is, "will headhunters poach this occupation and have a high success rate due to the salary delta?" And the answer for the EE -> SWE transition is obviously yes.