The ratio thing cuts both ways though. You said it yourself, the percolator cup tasted weaker, so you are not really getting the same drink for half the coffee, you are getting a worse drink for half the coffee. If you have to use more scoops or a finer grind to make the percolator taste as strong as your drip, the savings kind of vanish. Also percolators boil the water over and over through the grounds, which honestly can make it bitter or muddy if you walk away for two minutes. Your grandpa probably drank it black with sugar because that is what he grew up with, not because the pot made some amazing cup. Drip machines use more coffee but they are way more consistent, and consistent is worth something when you are half asleep at 6am.

Did the same on maple drawer fronts last year, 400 grit never touched them lol.

Wait, why would you stop using the laser when it's clearly working for you? Sounds like the old guy just wanted to feel right about his chalk line, and one ceiling doesn't prove his way is better for everything. Half those seasoned pros still do things the hard way out of habit, not because it's actually faster.