I think we've passed the era of most new electronic devices constantly coming down in price due to time passing. They were all already mass produced commodities with competition at each step of the chain 10 years ago.
On whether $100 is incredibly cheap/"chump change": It really is incredibly cheap, especially for a new electronic device you can use for thousands of hours over 9 years. That's not the same as a claim it's an easy expense for every person, if we become bound by that definition of cheap then there is no such price which everyone can easily afford and we lose the distinction. On that note, I often wonder if it's cheaper for libraries to just rent out ereaders than manage more physical book storage and exchange. I know my local library already does rentals but I'm not sure of the economics.
Companies gotta show increasing profit.
Once the market is saturated, you can't rely on selling more devices, even at lower prices. Companies have to turn to extracting more money from existing customers, like subscriptions and services.
That's not why. It's because Moore's Law died. Same reason we need 10x compute for each 2x performance increase from LLMs.
Where's GPT5 anyway? Isn't that supposed to be out by now? Sorry, that's not super relevant..
eBooks are expensive for libraries. Publishers are asshats and charge considerably more for eBook licences that expire after X uses or Y time, whichever comes first.