If that bothers you OP, take a look at your local opticians.
Almost every glasses frame has the name of a singer, or someone similar, on it.
My current glasses frame is apparently endorsed by 'Sting'.
I have no idea if putting your name on a make of glasses brings in the big bucks but I can't imagine there's any other reason for it.
Billie Eilish doesn't have to know anything about perfume, in the same way that Sting and all the other people who lend their names to such products know absolutely nothing about eye care.