If that was true, manufacturers would have been advertising 25, or least 10, 15, 20 year warranties to win customers.
Nobody putting their money where their mouth is is a better signal than anecdotal data.
As rule my Grandparents had stuff that was out of warranty, but having repairs done was cheaper than replacement. By my parents time things got replaced every 5-10 years.
In that time, I've replaced the dishwasher in 2014, a spring on the door of the dishwasher in 2022, and a heating element in the defrost circuit of the 1993 fridge. That's an oven, a cooktop, a fridge, a trash compactor, and a garbage disposal that all have 30 years of service, with only the dishwasher having failed and two repairs. Their older fridge in the basement is still chugging along as well. That's 5/7 perfect, 1/7 with one minor repair, and 1/7 failed inside of 30 years. My parents built their place in 1999; of the kitchen appliances, only the microwave has been repaired. Their place before that, built in 1974, only the dishwasher replaced between 1974 and 1998 when they moved.
My conclusion is that dishwashers sucked and still suck, but that old appliances generally chug along for decades.
I also think it's common sense that companies go out of business when there's no repeat buyers because their products last a lifetime.
I had not considered this, but I guess it would be a deterrent to offering long warranties.