Maybe you and I keep track of this stuff professionally or as a hobby, but most "grandmothers" don't. Quick: What's the best lock-in amplifier for rejecting mains interference. What? You don't know what dynamic reserve means? Jeez, you're such a dummy.
Think about how you would go about buying a piece of technical equipment outside your domain of expertise. That's what a "grandmother" is doing when he/she is buying a monitor.