Nice to know, though I wonder how many companies are really using all private images? I've certainly had a client running their own Harbor instance, but almost all others pulled from Docker Hub or Github (ghcr.io).
A lot of security is posturing and posing to legally cover your ass by following an almost arbitrary set of regulations. In practice, most end up running the same code as the rest of us anyway. People need to get stuff done.
My team’s service implements a number of performance and functionality improvements on top of your typical registry to support the company’s needs.
I can’t say much more than that sadly.