Are you kidding me? People have experienced losing oil and major leaks, had to replace engine for that? Oil leak at drain plug is not going to lead to major leak, much less to engine failure. It's the people who forgot to replace drain plug, then drove without ANY engine oil in it.
If there's any leak at drain plug, it's because people didn't tighten it with correct torque, not because they used cheap washer. Even if they didn't tightened it right, they're supposed to check for oil level every week, that's in your OM.
True, most on this forum probably check their oil on weekly basis and would catch an oil leak. And using a different washer probably not a big deal...would realize the leak and change out washers...
But sadly, a majority of the population probably doesn't even check their oil on a monthly basis, let alone weekly.
Add in someone who has a dirt or gravel driveway, parks in different parking spot at work... They might not even notice a slow drip til the engines blown.
Real world example, approx. 20 years ago, coworker was having trouble starting car, popped the hood... Battery was good, etc. No oil on dipstick...
Had crack in oil pan from whomever over-tightening the plug from last oil change...Lord knows how long ago that was. Yep that was expensive fix.
Of course he always checked the oil and didn't know how it leaked out that fast?
The little oil left that was leaking was black as coal and thin as water.
That's why they've designed sealed systems and longer lasting oils/fluids, for most of the general population that can't be bothered with maintenance.