I actually think Apple loves that you can use a Mac and iPhone this long and still be happy. It’s probably about the edge, because in today’s world security patching alone puts a huge burden at some point. But I think Apple wants its products to last and loves having users talk about their 8 year old Mac.
How many 8 year old Windows laptops exist?
How many people can talk fondly about even a four year old non-Mac laptop? Very few. Meanwhile, excluding the bad keyboard era blip, keeping a Mac for four years has been an easy choice since the SSD switch. Even 6 years is pretty easy for anyone who is just a bit careful with their laptop to ensure longevity.
I buy a new machine roughly every 2.5-3.5 years. I find this is the sweet spot for residual trade in value and meaningful upgrades. But it’s been a long time since I’ve felt a need to do that. Part of my loyalty to Apple products is precisely because they last. I think Apple knows this.