i'm thinking to add a feature where you can buy characters and that stay in your wallet for lifetime

so basically i noticed every platform provide you a timeline like one month or a year where after that time your credits will expire and you can't access your purchased characters well in first place this sounds like a business modell but i'm thiking from customer pov so it's better to have your purchased characters or coins access untill you fully utilised them , by the way what do you think