[bannable]

I'd think the decline of CTS is better explained by improvements in our material design: our interfaces with the physical world are much less hostile today than in '90 and cause us less harm. For example, consider the NES/N64 controllers versus a modern PS5 controller.

[conception]

I dunno. Cheap keyboards are definitely worse today.

[stubish]

Most people are also using keyboards less, spending more time waggling their mouse or having a break watching youtube. And people who are mostly employed to type, doing data entry or similar, have problems and physical therapists who understand the problems.

Carpel tunnel and RSI also predates computers. Musicians still suffer this sort of injury, generally by forcing themselves to keep playing when it hurts. Poor computer ergonomics just made it popular.