I'd put it differently, "you can't have used without the new". They might not be all that different in practice but you can't have everyone buying used. For every used unit sold, someone had to buy it new first.
I agree with the rest. Having a bunch of RPi up to RPi4 in the house, I'm having a harder time finding its proper niche. I don't need the GPIO or the relatively small footprint in general, and from power and performance perspective it doesn't have an edge anymore. RPis stopped excelling at many things they used to, as the price to fix some of the bigger downsides. It just doesn't strike the best compromise for most of my uses (same from what my RPi-fan friends tell me).
But despite reviews like this everyone should make their own assessment. There's no one size fits all. I run a RPi because I could power via PoE. Another one because there was no room for anything larger.