I want to start an appliance company that offers 10 year warranties with an additional 5 year replaceable parts availability promise. The designs will be simple, functionality simple with minimal quality of life improvements, and all repair manuals will be published on the website along with tutorial videos, while also banking on building a product that simply lasts longer.

I’m willing to bet that if that is what you advertise on, the longevity of the product at a minimal price, then the company should do fine.