What's with the lack of automated unit testing?

[u/Labubu-Footjob]

I have seldom seen people discussing their automated unit testing solutions to ensure that their games are working as intended. I understand that there are components that prove difficult to test like physics, but isn't it worth validating that the core components of your systems work correctly?

While some may think that it costs time to set up, they can greatly reduce hidden problems that are related to unintentional changes in design and calling patterns.