Alright I’ll just head over to the dictionary.

Emphasis mine, as long as the item is periodic in nature it’s a subscription. The SQLite online membership has a term of access so it’s a subscription.

3: an arrangement for providing, receiving, or making use of something of a continuing or periodic nature especially on a prepayment plan: such as

a: a purchase by prepayment for a certain number of regular deliveries of something (such as issues of a periodical) or for a certain period of access to or use of something (such as an online service)

b: application to purchase securities of a new issue

c: a method of offering or presenting a series of public performances d (British): membership dues