your example with the fridge is only half of the issue.
In software, you can patent very broad concepts.
Whereas in hardware you can mostly patent function.
For example, you can patent a new compressor design, that runs on unicorn farts, for your fridge and sell it.
But you cannot create a patent in a way that prohibits other inventers from also developing a UF-compresser for fridges, as long as it differs substatially from yours.
In software, you can patent whatever you want.
Example Amazon has a 1 click payment patent - and the patent doesn't cover the software and hardware required to pay with one click (as the Unicorn fridge did) - nope, it is a patent describing the concept of using an UI element to make an instantanious checkout
Below i've attached a patent that's describes a person using a "communication media" to connect a database of merchants.
- this is basically online sales, online ads and online phonebooks, all in one patent.
View attachment 1714889
So yeah, in a perfect world, people would only sell ideas and licences to ideas.
In the real world, apple managed to patent a rectangle with rounded edges.