My experience? unless you have like a bottom quintile boss, you can tell him/her almost anything, if you do it verbally, with the door closed.
I mean, in most cases, yeah, I'm technically more skilled than the boss... and the boss knows it, that's why I was hired. The fact that the boss hires people who are more technically skilled than they are means that the boss is good at their job.
Now, of course, there might be other issues related to the business or to other systems that I don't know about... the boss might not take my advice, but only a terrible boss won't listen to the advice of a technical individual contributor that they hired.
the places where I've seen people get in trouble for arguing with the boss is when they do it angrily and publicly, and when they don't get over it after the boss explains why it has to be another way.
As an employee, if you object to something your boss is really on board with, you can expect to be fired.
It is, in general, a career limiting move to tell anyone above you that what they're asking you to do is stupid. Maybe if you're a God-tier management consultant, you can propose changes and expect to have them implemented. As a regular employee or contractor schlub, no. If you want to keep your job, adopt their perspective.
(Illegal actions are another issue. While it's illegal in many jurisdictions to fire a whistleblower, in practice you're still risking your job to blow the whistle. Not that you shouldn't do it.)