A large bank will perform risk analyses and consult with their data and math people, consult their legal people, consult their insurance people, and will choose what they think is best.
So your option can be totally feasible and never chosen by a large bank- a similar fate to many new technically feasible ideas.
But then again, if you were a large entity, would you prefer to be indebted to one large entity, or a thousand small ones? All things equal, I'd rather owe 1 person 1000$ than 1000 people 1$, and I imagine their lawyers and insurance people agree.
Now you could replace banks with e.g bonds sold in the public market, but you still need something to finance the IT of the world.
Their revenue is many times that, certainly, but that doesn't mean they just have billions of dollars lying about doing nothing, waiting for the company to need a factory.
Also I am going to have to ask for a source for your hypothetical reply.
Sure, in fact, the same loan probably will be with the existing system. Large (hundreds of millions of USD) bond offerings to the public, from either a state agencies or private firms don't end up with only one purchaser in many cases, even if they have a big financial firm facilitating the offering.
The question is how do alternative mechanisms do this as well or better?