This is what happens inside of a Diep.io Factory.
Shapez.io, an automated Factory game that is available on Steam. The goal is optimise your factory base as much as possible. There are infinite resources (except for copy and pasting the production layout) so resources and the amount of buildings is not an issue.
I wouldn't call this an .io game, it takes some elements from the popular game Factorio, but it's still a good game nonetheless.
Discord: / discord
Music from Epidemic Sound (http://www.epidemicsound.com)