Does this mean that it's OK for an employer to put cameras in employee bathrooms? The argument can be made that it's not the employers responsibility to provide me with unfettered access to a space to do personal stuff with, just like internet access, so why not?

If the employer needs to back-door encryption to discover your personal activity, how is it their business what you are doing? Your activities obviously caused them no public issues. If they did, the encryption back-door would not have been necessary for the discovery.

In more civilized areas of the world privacy rights are explicit, and even things like employers snooping on employee email accounts on company owned email servers is illegal. When at work, you are selling your time to your employer, but that doesn't imply that the employer owns you while you are at work.

As to the sibling comment about cameras in workplace bathrooms, yes employers did this and now there are laws prohibiting it. Now, employers just account all your time using bossware leading to e.g., folks at Amazon having to pee in bottles or wear diapers on the job to not get fired. There is no line that some capitalist employer will not cross unless we place limits with consequences to reign them in-- e.g., we no longer have employers forcing small children to crawl into running machine tools to clear a jam while risking a limb being sucked into the mechanism and turned into hamburger meat-- but, we did, it was common-- lives of the poor (especially children) were cheap, but stopping an assembly line was expensive.