This largely was the case in software in the '80s-'10s (when versions largely disappeared) and still is the case in hardware. iPhone 17 will certainly cost far more to develop than did iPhone 10 or 5. iPhone 5 cost far more than 3G, etc.
You could see here: https://www.reddit.com/r/dataisbeautiful/comments/16dr1kb/oc...
new ones are generally cheaper if adjusted for inflation. This is a sale price, but assuming that margins stay the same it should reflect the manufacturing price. And from what I remember about apple earnings their margins increased over time, so it means the new phones are even cheaper. Which kind of makes sense.
I am expecting AI companies to start using ads, it's inevitable as they need to make money at some point and $20 a month won't do it.
For ads the number of users is the main thing - the more users you have the bigger the market and more money you could earn. Google desperately needs to be in this space, that's why they are throwing a ton of money on AI.