What has changed in the last 5 years? MacOS users have no legitimate alternative if they want to keep their desktop on macOS. If you want a macOS system legally, there's two options, either buy a new Mac, or an old one.
The competition has just done a lot of catching up in the last few years.
Hardware: Other vendors have trackpads with multi-touch (which for me was one of the most amazing things about the first Macbook I ever owned), super high-res screens, and other such features these days. The form factors are thin and stylish as well (there are other aluminum unibody laptops these days).
Software: MacOS has gotten worse, Linux distros have continued to catch up, both in the look and behavior of the OS itself but also in terms of the app ecosystem, esp with companies like Valve spending the big bucks to get lots of games running well on Linux. Speaking of games, MacOS continues to suck when it comes to gaming anyway – so for example I do a bit of gaming on my new MBP 16" and the mild chore of dual-booting continues to irk me. I also splashed out for the 8GB GPU upgrade and performance is still not great. Not quite enough for me to make the switch but I'm not a very hardcore gamer. I know people that need a workhorse a bit more than I do (professional video editors and such) who have recently (last 5 years) made the switch from macbooks to things like razers because they want to be able to really push through serious workloads on the go.
We're not on the same page. My point being that the macOS users that Apple are targeting with this policy has the choice between a new Mac and an used one.
That's where they make their money. People that just want good specs at cheap prices are not their target market.
Replying from my 6 year old Macbook pro, I would definitely consider buying a new one (space on my 256 GB SSD is getting tight, and it seems a bit of a waste to just upgrade that), but I am hesitant about the newer models.
Maybe true 5-10 years ago, but not true now.