Proper Capitalism is supposed to fix price gouging.
Apple et al put up their prices... Others step in and undercut them because they can make a similar product much cheaper.
Except it happens less than you might expect because, in a rich country like the UK, it is like people paying twice as much for a loaf of bread that really isn't much better than the cheaper one. They pay the premium because it is not actually a break-the-bank kind of extra cost.
So, the people that buy the new phone are usually people with a lot of money to spare - I see huge numbers of people with old iPhones, broken screens, cables hanging out of their pockets because they require power blocks to keep them running.
Of course, there is probably a general trend downward as harder times bite but this is still a rich country and Apple/Samsung will still have a market at the high end.
Me, older phone not Apple or Samsung and I prefer it that way of course, because I could pay the premium if I wanted, I just don't want.
Older phones have so many useful selling points, the main one being less worry about dropping/losing/stealing. No case required. No fear that some twat will rip it off. No worry that it is going out of date soon. Really, much less stressful.
And, since no compelling additions have been made to phones to make one wish one had the newest shiny, even fewer issues. Screens still remain similar or lower res than mine (564ppi), cameras are similar or worse (20MP Zeiss), unlock with a face/iris, yeah, super useful. Tons of RAM, tons of Flash.
The only real USPs that would make me want to move are:
1. Essentially unbreakable, although I have dropped mine several times, caseless, and the glass remains unblemished.
2. Power breakthrough, a new tech that makes a phone last, say, a week. My battery is removable already so new battery tech could conceivably be used anyway.
3. Running PC apps, real ones. Not critical but I would just have one because it would remove the need to have a Surface or a laptop in many (more) cases.
As long as it remains supported and updated, which mine still is, at least monthly, I will stick with it.