I use them too. Sometimes I like to have some repos with the static content, which get deployed by a CD tool to those services. It's common for me when debugging or testing locally in my PC or LAN, to include some docker build for those repos which I don't use at production time, but I used it locally. Maybe is not a big problem at all, but I use it that way, specially when in my projects the CND used is not a free one. Makes sense?