There is no nuance, no leeway, and no way for you to reason your case with a thinking human on the other side of the decision. The algorithms & systems are also almost always completely opaque in their workings, with neither the person on the receiving end nor the company's staff having any insight into why they made decisions or what data was used.
Using algorithms for life-affecting decisions like this would not be nearly as bad if you had a reasonable ability to appeal and have the decision be taken as final.
It doesn't even have to be AI, or an algorithm. The British Post Office Horizon scandal is an example of lives ruined by an assumption that accounting software could never be wrong.