Also game dev here - I disagree with your take. Our _build tools_ need to be hyper aware but our CI systems absolutely do not and would be better served as general purpose. What good is Horde when you need to deploy your already packaged game to steam via steamcmd, or when you need to update a remote config file for a content hotfix. Horde used BuildGraph meaning you need a full engine sync’ed node to run curl -X POST whatever.com

Game dev has a serious case of NIH - sometimes for good reasons but in lots of cases it’s because things have been set up in a way that makes changing that impractical. Using UBA as an example - FastBuild, Incredibuild, SNDBS Sccache all exist as either caching or distribution systems. Compiling a game engine isn’t much different to compiling a web browser (which ninja was written for).

I’ve worked at two game studios where we’ve used general purpose CI systems and been able to push out builds in < 15 minutes. Horde and UBA exist to handle how epic are doing things internally, rather than as an inherent requirement on how to use the tools effectively. If you don’t have the same constraints as developing Unreal Engine (and Fortnite) then you don’t have the same needs.

(I worked for epic when horde came online, but don’t any more).