Consumers undercount the true total cost. And because X% of people will forget they're subscribed and keep paying forever.
If every month you had to either consent to recurring charge on your card or unsubscribe, I'm sure billions of revenue would evaporate overnight from people mass unsubscribing.
(I wish there was regulation that required companies to automatically pause monthly subscriptions if you haven't logged in to or used the service in any way for 3+ months. Though that would create some weird incentives)