Equal work for equal pay is important, yes.
Businesses might be willing to “give a chance” to someone with a disability if they don’t have to pay them as much as anyone else.
If there are no other incentives, and someone with a disability is unable to perform the job as well as someone without a disability, then the business would likely choose the more capable employee regardless of any disabilities. And by definition, that’d usually be an advantage for the person without a disability.
You can’t fire someone for having a disability in a lot of places. You can usually fire someone for not performing well enough at the required duties.
And if it could be trained ethically, it’d be more ethical, too!