If you're running Windows, it's built into the OS using Group Policy. Very helpful when a company is running it's own internal CA/PKI.
https://www.jamf.com/jamf-nation/discussions/11830/deploying...
Other applications on mac/linux that use their own keystore like OpenSSL or Java will throw cert errors if you don't also install the CA in their keystores, but that could be scripted as well if it causes too much friction for users.
If you're in such an environment, the options are either install the CA or don't use anything that requires HTTPS ¯\_(ツ)_/¯