I've travelled to 50+ countries and never considered bringing a burner device. This recent US thing of of checking your devices or social media posts and turning back people with wrongthink is kind of novel.
I worked for a government contractor and this was common guidance over a decade ago if you are in any sensitive role
It is not hard to imagine a scenario where a foreign government might surreptitiously plant a rootkit on a lowly IT workers device as they transit customs, as a means to pivot for corporate or other espionage
It is much more common to phish the administrative staff for a firm to get network access but you would have to be a fool to ignore the vector of customs simply using direct physical access for a much more effective hack
I just realized that the most restrictive border I ever crossed was a trip to Tel Aviv and it was well known even back then that they would inspect everything about you before you even landed
