> So what is it about subscription that makes this impossible?
Just the nature of it? A subscription is always going to be a regular fee that pays for an aggregate of multiple things, some of which aren’t used by every subscriber. (And which some subscribers are going to object to paying for.) The only way to ensure that you only pay for what you use is a pay-per-use model.
And conceptually I really like pay-per-use models, but the public tends not to love them - in particular for things with low marginal costs of production/serving, like software services. (As opposed to medium marginal-cost goods, like say, home gas utility, where non-usage-based pricing is available, but tends to be poor value.)
Just the nature of it? A subscription is always going to be a regular fee that pays for an aggregate of multiple things, some of which aren’t used by every subscriber. (And which some subscribers are going to object to paying for.) The only way to ensure that you only pay for what you use is a pay-per-use model.
And conceptually I really like pay-per-use models, but the public tends not to love them - in particular for things with low marginal costs of production/serving, like software services. (As opposed to medium marginal-cost goods, like say, home gas utility, where non-usage-based pricing is available, but tends to be poor value.)