Is baggage wrap a waste of money?

Question

My checked bag(s) have been opened on every flight from/to USA and on some others. So I would think plastic wrap would be a waste of money. Especially if it increases the probability of inspection ("maybe this guy is trying to hide something").

Answer 1

Well:

My checked bag(s) have been opened on every flight from/to USA and on some others

^{(emphasis mine)}

Scope of the plastic wrap is to preserve your baggage from scratches and to keep things inside in case of zip/lock failures, so if it's worthy is up to every one's taste.

But, given your premises, it's clearly and objectively a total waste of money because it will never be able to fulfill its task.