Why not make state and federal social welfare relationships one-on-one instead of collective?

When everything is reduced to essentials, there are people who receive individual welfare payments of one sort or another, and there are other people who are forced to make those payments through taxation.
As it stands, all the money is taken from one group, dumped into a pot, and then passed out to the other group.
If this is inevitable, why not simply save administrative money and assign one specific recipient to one or two or however many specific payers?
The payers would be required to visit the recipient once or twice a month and give them their money.
The net effect is the same, the bureaucracy shrinks, postage is saved, and at least the possibility of a relationship exists.
I wonder why they do not do it that way?