iCloud storage

These are user community forums, so we are not Apple employees.

iCloud subscriptions are month by month and your additional storage will be available for as long as you continue to pay each month. You can cancel a subscription at any time.

iCloud storage subscriptions -> iCloud storage plans and pricing - Apple Support

No. Apple discontinued the annual plans some years ago now. There are only the monthly subscriptions now.

Cloud based storage and compute systems cost money to run (electricity, cooling for server farms, maintenance and repair, etc) so companies charge recurring fees for access to them. They also represent a massive investment that has to be paid for - Apple has reportedly invested more than $10 billion in their iCloud system in the last several years.