Contractor teams end up staffed largely with builders who are held accountable for what they build not shipping, but it usually isn't shipping because it's held up by approval processes outside of the sphere of influence in which the contractor operates. Outside that sphere, feds tasked with releasing on a timeline end up frequently confused by perceived reticence on the part of the contractor--"why aren't they getting this bugfix out the door ASAP?" (answer: they are only often staffed for/limited in authority to building the thing and throwing it over the wall, not making sure it goes live).
What you get as a result is a situation where a cross-context group like the Digital Service is often the only way to speed up those bottlenecked processes. In other words, the problem was the failure at "getting us in contact with other gov folks to speed up releasing the fix", not the coding of the fix itself.
The larger solution to that failure mode is to fix the accountability matrix (I'll never stop linking to this article, which sums it up so well: https://www.eatingpolicy.com/p/understanding-the-cascade-of-...). That can mean a lot of things. It might mean that contractors are staffed/expected to work with fed shareholders running the release/approval processes to get their changes actually shipped. It might mean that federal departments bring more "build" or "technically own product delivery" expertise in-house. It might mean fixing/streamlining approval processes (this is lot harder than it sounds).