This is a rationalisation. Your "reasoning" could apply to anything that is transacted at any point in history, but the conclusion does not apply to all those things. "You're not paying for one banana, Michael, you're paying for someone's mind having thought up the idea of a banana plantation"
Well a banana is a thing. You can have ten bananas in stock. You don't have ten softwares in stock. Unless you put it on a carrier and sell it one at a time, like a painting. Software is quite unique when you go the subscription route. What is it you're buying, really? You're buying human labor that was automated, so you don't pay for the labor, but for not having to hire someone. That makes it so unique...
I'm still paying for the product, not for the invention of the concept of the product.
Matching different payment models is pretty common in business, not some weird thing that only applies to software. A buffet takes a fixed price per customer, and tries to match it to the actual amount of food the average customer eats. A bank (at least in pre-fiat currency) takes money for short unpredictable periods of time and lends it out for long fixed periods. A hotel takes a variable price per night and matches it to their fixed cost of rent, maintenance and cleaning. An ISP takes a fixed monthly fee, and tries to match it to how much data transfer the customer causes and where the data is flowing. An airline takes a variable price per customer and matches it to their largely-fixed cost of flying the plane. And these new-age software companies take a fixed monthly fee per user and match it to a one-time development cost.
I mean - yes, that is what you're paying for. Bananas, like all products, are engineered.
There was the original domestication, and then there's the modern industrial process of plantation management, picking, shipping, and distribution.
All of which has to be invented, implemented, and organised.
You can - and probably should - question the ethics of same.
But that doesn't change the fact that most places that want bananas do not have have bananas, and making bananas happen in non-banana locations is a very complex process.
Good ideas and organisational ability don't grow on trees.