It’s called inflation. You’d expect to pay the same price as you did 10 years ago? It was the best phone at $599 because it was the only phone. The 8 is far better then most phones on the market and that’s priced at exactly what inflation costs would be from 2007-2017. Apple isn’t cornering you into one phone priced at $999. You have cheaper options. If you want the premium tech you’re going to pay a premium price. It’s very basic knowledge.
The iPhone was hardly the "only phone" 10 years ago... not sure where you got that idea from. In your "basic knowledge", did you discover that typically prices of technology go down, not up? So in most cases you see prices stay around the same point with each cycle as the products get more features and faster. Few are going to buy a iPhone X without AppleCare because of the insane prices to replace the back of it ($549). So you are paying over $1000. I think Apple is finding that most people are not willing to spend over $1000 for a phone.