I mean, every team would always love to have more employees (if only managing costs weren't a thing), but that's not really the issue here. Making large-scale software is complex, and there are a lot of factors that go into it.
It's not just a matter of the raw data entry side (which, as you say, can get done in an afternoon), it's also about the build & deploy loops necessary to get it to QA for testing, their test time, and making any fixes. Now that we know it's properly built, it's ready to go into a build, which involves a whole additional round of steps.
It's not really a person-power problem, it's the fact that big things are complex. And there are ways to cut through that complexity and build special channels, but that also takes time. That's what we're working on here.