HN user
It's not clear to me that your experience was unethical. As parents are the legal guardians of kids, where is the responsibility -- to the adult, or to the child?
Your third paragraph is very hyperbolic and taints the otherwise reasonable points I believe you made.
I think you'd have to include a large majority of IT personnel in this figure, as they are the likely first line of support for many windows installs.
That number is probably much higher than 1 million.
Apples to oranges, of course. The interesting part is that MS scaled their support to include people paid by their customers directly because their software was so business critical.
I would caution against calling it depression, which is a set of symptoms classified as a disease and really can only be evaluated by a professional.
However, I recently went through a period of anhedonia (https://en.wikipedia.org/wiki/Anhedonia), which may be what OP is experiencing.
Things that I found that worked: exercise for pleasure (riding my bike!). Connecting with people (one-on-one -- i'd always been part of a big group before). Learning new things, new challenges. Yoga.
A book that helped me a lot was Frankl's "A man's search for meaning". I realized that I had a bit of fight club nihilism in me because I never chose my purpose in life, and so was just sitting on the metaphorical treadmill of existentialistic wallowing.