I share these frustrations. From what I know, I am the only one with a plugin for running unit tests graphically. However, I have to run this manually it in Roblox Studio. I have no way of running them as part of a CI/CD workflow to roll out game or model updates, which means I have no safety system for pushing out an update with major game-breaking bugs.
I have used unit testing on critical systems like data storage to simulate many error scenarios and 2 servers communicating data. Rather than hoping for the best when a scenario happens with actual players, I can quickly and repeatable test it ahead of time. It has saved me a huge amount of time and headaches with issues that would have only come up in-game later. It only works as long as I manually run the tests before releasing code. I want unit testing/automation testing to become a more known and practiced topic because it has saved me a lot during outages. This is more difficult without being able to do what is expected with many other industry testing tools.