It means prosperity in the sense that the manufacturer is taking you to the cleaners by eliminating smaller low-end and mid-range products to funnel you into higher margin "big" things, for both cars and phones.

SUVs being pushed so aggressively the US is because the margins are better and the segment is eternally protected by the Chicken Tax. The insane CAFE leniency for lardassed SUVs/"light trucks" is fought for tooth and nail because the margins on SUVs (especially full-size ones) are crazy.

Same thing happened with phones. Remember when a thousand dollar phone was stupid? Now that's what shit gets developed on, tested on, etc. It's just normal, and that's great for people who make phones.

Not enough modest people exist to really make an impact in sales numbers and even if they did, they don't really drive any more sales. I know multiple people that are very well off, money in the bank, with a nice house, multiple very nice (enthusiast) cars, that just don't give off the same FOMO effect as somebody in a shitload of debt living in a McMansion driving around a shiny new Navigator.