At least in Austria Cash vouchers have a loong expiration date. Except if they are tied to a timed offer. But general cash vouchers are valid for multiple years. (Recently used a voucher for a restaurant that was over 3 years old)Do gift cards and cash vouchers have no expiration date in your country?
This is no different from cash vouchers that expire after a certain duration and has been the case for most physical shops.
Not that I I wouldn't mind vouchers that have no expiry date but I think a 1 or 2 year time frame is fair.
For example, Uniqlo here sells gift cards that expire in 6 months. It's quite ridiculous.