I’d like to see an example of a healthy romance that doesn’t involve friendship.

You won’t find one because that wouldn’t be healthy, but it is the kind of transactional relationships those who are heavily invested in the idea of “the friendzone” are looking for. They do think friendship is lesser, and don’t want an equal partner and friend, they want a subservient housekeeper they can also fuck, and maybe even smack around occasionally as am outlet for their frustration with the world.