Because if I bought a new phone last year, why would I want to spend money to buy a new phone now that's worse than what I already had?
Telling someone to buy an iPhone because of this is pretentious. Telling them to buy an iPhone that may be worse performance wise than their current phone is way worse.
It seems like in your original post, you were saying that iPhone was not a good value. Yet the A series chips consistently outperform Snapdragon by years, and software support for iPhone probably means a years old model has more official life than a latest Android.
I don’t think the reply was suggesting you get a new phone specifically. They were responding to your claim that iPhone is on face not a good value.
No, I wasn't saying it's not a good value. I was saying it's a ridiculous thing to ask of someone that may have a completely serviceable phone that might even be brand new. It's like telling someone to buy a Mercedes or Volvo. It may be a very good product, but that doesn't mean there's not a lot of assumptions in any recommendation to buy one, especially if it doesn't consider the quality, cost or age of your current car other than "not a Mercedes or Volvo".
Except in this case you can buy iPhone for $450 which is less than the OnePlus6 in my locale. SOCs compare favorably between the two devices. I guess I’m not seeing why iPhone is akin to a luxury car brand.