OP referenced benefits from accommodations for employees who aren't recognized as disabled, so it seems pretty clear we're outside of the legal framework for workers with disabilities.

And, generally, they do buy those things for themselves. Though plenty of employers will allow employees to expense these sorts of things, along with tools like ergonomic keyboards. They're cheap, in comparison to the cost of employees.

Hell, maybe that's the example I should have led with. Some non-disabling health conditions might put someone at a heightened risk for carpal tunnel syndrome. Ergonomic tools seems like a no brainer, compared to hardship and learning to work harder.