“Someone” might, but most people won’t. Do you think studios are going to announce the next blockbuster and most people will be like “eh, I’ll just wait 20 years, maybe I’ll have a kid and raise them until adulthood to pass the time”?
Portal is going to be 20 next year. I bought Portal 1 and 2 for a couple of bucks like a decade ago already.
I’d even say 20 years default is two long. Especially because there are things which are just abandoned. Make it shorter and add limited options to renew for limited time.