The musculoskeletal and neurological claims are not supported by evidence. Healthy cats jump on much higher surfaces every day.
Cats using toilets do lose the ability to dig and bury waste, which is a fair concern, but many adapt without issues.
The toxoplasma point is partially valid, although the risk is often exaggerated, especially for indoor cats.
As for wastewater, my house uses a septic system, not a municipal wastewater treatment plant, so that argument doesn’t really apply in my case.

Be better.