They used leaded solder. I’d hardly call that cutting corners.

As a newbie solderer, I can say with certainty that the overwhelming majority of hand soldering is leaded. All the experts and all the advice out there recommends using leaded solder, especially to beginners because “it’s easier to work with” (anecdotally, I haven’t found that to be the case, but that’s another story)

Not saying these devices are hand soldered, just that using leaded solder is far more common than you’d think