The latter makes us establish physical security around election polling sites, and the former requires that we spent money to move people, machines, and consumables into and out of those sites.
As such, those costs require that political districts consider geography as a practical, money-saving measure, especially roads and buildings. You have to print N blank ballots and send them to the polling stations, and then send back any unused blanks, and the local issues on ballots for adjacent districts might be different.
In order to eliminate geography, you would need a system that has good data security without requiring physical security for the whole network. And an integral part of that would be a foolproof and uncheatable online identification system.
Good luck with that.