This is the side effect of lazy teaching. Unique tests cannot be leaked. Problem solved.
Or maybe don't do stupid tests for computer science.
This is a space where whiteboarding is a good idea, in fact, interactive whiteboarding with a whole class is a great way to teach and work through problems.
Any type of interactive test is hard to fake.
The result? The final contained a majority of questions from that cheat sheet. I still pose this scenario to a couple friends nowadays asking if this would be considered cheating, and the responses are actually a mix of "no, you're just taking what's publicly available" and "yes, you're manipulating the system to get where you are and taking spots from someone with academic integrity".
As others have said, we go to college these days for a fastpass to middle class. If you haven’t needed the knowledge since, maybe you got what you needed out of the class and you worked the system in a legal way. Or maybe you paid a lot of money for that class and yet cheated yourself out of the knowledge you were paying to be taught. On some level it comes down to how you feel about it.
I have never heard of lazy teachers ever getting any consequences, so why should they stop doing these things? You could make it a part of their job, but of course lazy principals wont do that either. There just aren't any incentives to run a school properly.
Teachers go to learn how to teach, in the abstract sense, for 4 years, to go to teach high school kids. They learn the techniques and tools to effectively translate subjects and educate people.
Professors do not do this.