Half of Europe does, it's just that everyone talks about the US like it's a special case because those searches happen routinely. It's legal to search a phone without reasonable suspicion at airports in the UK under the Terrorism act 2000 (pre-9/11!)
I really hate that these kinds of justifications almost always ends up to serve as a push for acceptance through apathy of the status-quo, as opposed to fueling that outrage that pushes for positive change.
UK is not europe
UK definitely is in Europe, which is not the same as the European Union. Like Switzerland for example.