There's definitely reasons: profit = revenue - costs. If revenue is fixed, the only way to make more money is to reduce costs. Using cheaper parts with less/no

There's definitely reasons: profit = revenue - costs. If revenue is fixed, the only way to make more money is to reduce costs. Using cheaper parts with less/nonexistent quality control is one way to do that. Or even just straight up laziness. The "trust but verify" approach is more work than just trusting your suppliers to never make mistakes.