(Try pouring out your biggest spinning rust drive out over any port that can keep up with the drive. It takes hours nowadays. SSDs can bottleneck at the port instead of the drive, but you can't count on your target having one yet, nor can you count on the fastest ports being available. And we're certainly not going to mass-disassemble laptops to dump their drives.)
[0] https://www.schneier.com/blog/archives/2014/06/building_retr...
And, still, at bulk these things aren't feasible, or even necessary. You're not taking your cynicism far enough. Why does the government need to sorta kinda hope that you might maybe take a flight with your gear someday when they're already capturing all your email and web browsing anyhow? It's a ridiculous theory that you're only entertaining because our trust has decayed to the point that the mere fact that something is an accusation against our government is all but proof that it must be true, no matter how silly it is.
No, the government is not going to set out to physically attack every laptop passing through an airport, because what would that give them that they don't already have, except huge operational costs and risk of detection?
Or maybe make even more feel yet more in fear of terrorists. Which the cynic in me thinks might be the point