Gift cards are very limited. The tech behind gift card usage is extremely insufficient. Things like checking balance is often not even possible with a public API layer.
Not only is this a solution in search of a problem, it's a solution which hasn't found a problem, and is being shoehorned onto problems it actually exacerbates. If you're running a business, the last thing you want is for your business' systems to be decentralized, because that means you don't have control over them. There's literally only downsides for the business.
Why not just skip all that nonsense and build a token? It's an easier abstraction and does not involve asking permission or trusting a third party.