Are Spies More Trouble Than They're Worth? (2019)

Usually "yes". Often "hell, yes".

And when spies are actually well worth the trouble, that is usually due to extraordinary circumstances - an existential threat to the nation employing them, a George Washington (99th-percentile competent and honest leader) in charge of the spy agency, or something else that can't be sustained nor reproduced.

But the temptation to spy, fears about spies, etc. - those mash so many human emotional buttons that I wouldn't expect any nation to actually pursue a rational policy in this area.