What's the "lifetime" of a graphics card?
As in, lifetime doesn't mean your lifetime. Or the time you own the card. It means whatever expected lifetime the item has as per the manufacturer. The manufacturer may define the "regular lifetime" of their item to be 3 years for example and then it would not have helped you at all.
I've never registered for any warranties in my life.
I'm not sure if this is a thing where you are. But where I am for example, there are warranties guaranteed by law that require manufacturers to warranty their items for a "reasonable" amount of time (regardless of what their actual terms say). What is reasonable is up to interpretation and different for different items. They do give a few examples for common items like a washing machine but otherwise it's up to consumers and companies to figure this out together and if they can't you can make an official complaint with the government. Helped me w/ NVIDIA who wouldn't replace a broken tablet shortly after their official warranty ran out.
EDIT: No idea on the downvotes, when I started replying there were no downvotes yet, when I submitted there was.