Alternative paper banknotes that is unregulated by the government sounds like just counterfeit money.

I mean I wouldn't say I won't use it but it would need to become very popular. For example, back in my childhood McDonald started a new campaign and they were giving out paper money for their business, it wasn't actually "money" but just coupons to be spent there, there was some menu options where you give the ticket and they give you menu and there were just plain of "this much amount" type tickets as well.

If there was a bigger version of this than I would totally use it too. There was a huge gift card company that went bankrupt here but their gift cards were capable of using anywhere you go and you can buy anything you want with it. People started to give gift cards to each other as presents so that person could go to any shop they want and get anything they like. So there are similar ideas.