The government has lots of employees who came from the private sector and know exactly how that side of the house works. They aren't really this disjointed set of workers.
IMO, a lot of the differences come from the different set of rules that govt work has to run by. For example, Aldi can just decide to hire a contractor that they know does good work at a reasonable price. In contrast, the govt has to use a lengthy fair and open bid process and if they want to select a bid that isn't the lowest, it's a painstaking process to justify that selection. Govt work must adhere to certain laws that tend to push up labor wages (see: Davis Bacon Act). Plus, the govt has lots of other competing goals, like supporting minority or veteran-owned business etc. A simple comparison misses all of those nuances.
IMO, a lot of the differences come from the different set of rules that govt work has to run by. For example, Aldi can just decide to hire a contractor that they know does good work at a reasonable price. In contrast, the govt has to use a lengthy fair and open bid process and if they want to select a bid that isn't the lowest, it's a painstaking process to justify that selection. Govt work must adhere to certain laws that tend to push up labor wages (see: Davis Bacon Act). Plus, the govt has lots of other competing goals, like supporting minority or veteran-owned business etc. A simple comparison misses all of those nuances.