My $12 outlet tester caught a mistake the home inspector missed

I bought one of those little three prong outlet testers at the hardware store in Akron for 12 bucks after we moved into this 1960s house. First room I checked, the kitchen counter outlet showed as grounded but when I actually pulled the cover plate the ground wire was just twisted off and tucked in the back, not connected to anything. That tester told me the wiring was fine but it was lying, the dumb thing only checks voltage differences. Turns out there was also a reversed polarity issue on the same circuit that could have fried my new fridge. Anyone else ever had a cheap tester give false confidence and had to dig deeper with a multimeter?