Should I accept affiliate marketing as payment?

No!

Well, having an affiliate link is okay, but you should also get paid. Especially if the brand’s affiliate program is available to anybody on the internet to sign up for.

If you’re trying to work with a brand, and they say they won’t pay you, but they will give you an affiliate link with some percentage commission, go ahead and take a look at their website. Check if they have an affiliate program that anybody can sign up for. Check if the commission for that affiliate program is the same as the commission they’re offering you. If it is, they aren’t giving you shit, so you shouldn’t give them shit.