With a few exceptions it's much easier to either poach your competitors or simply buy them outright which is why "corporate espionage" is mainly employed by nation states these days that need to catch up. It's also important to note that stealing a design isn't that useful these days since you are too far gone what would be more important especially in the semi industry is to know the characteristics of a specific design or process in order to be able to preemptively position your offerings to compete without giving up any unnecessary ground.
In a restricted environment you will have several monitoring agents that track and enforce system integrity.
https://docs.microsoft.com/en-us/windows-server/identity/sec...
Example of an actual implementation in the wild: https://uit.stanford.edu/service/paw
The only machines that can actually SSH into prod at least have screen-session-recording software, perhaps are kept in a separate room, with a policy of two staff present at all times. The general idea is that the closer you actually get to being able to bypass the checks and controls, the more attention you bring to yourself and your errand.
Yes, it can't be Git and Puppet all the way down, at some point someone will necessarily have access to do something as root on the server that hosts the Git repo that Puppet runs from. But instead of that being every dev on every laptop anywhere in the world, you can make sure it's a very small group of people, from a small number of workstations.
This is difficult and requires a substantial and very competent team to implement correctly.
A move I've seen being put in place at several locations, is removing local admin rights from all users. Those with advanced needs, like developers, gets a VM which is limited to a specific VLAN, with no access to the production environments.
The principle is sound, implementation is ... difficult, to say the least.