They are time limited, but so is the need for them. The point is to have
options where your screen reader of choice doesn't work. Greater
accessibility is created by greater choices.
It's an issue with an application, a web page, or a procedure.
Since nvda and system access are not time limited, that objection is removed
as well. The point is to be a controller of your access to things, rather
than being a victim of your inaccess to things. accessibility like ham
radio, is an art of finding ways to get things done, over challenges.