Earlier quoted context omitted.
Not to mention if you build your own PC you can upgrade the parts as and when, unlike with the new Mac where you'll eventually just be replacing the whole thing.
I believed that until I realized I couldn't individually upgrade my CPU or RAM because I have a mobo with LGA1150 socket and only supports DDR3 (and it's only 6 years old). So eventually you still have to "replace everything" to upgrade a PC.
To do CPU upgrades you eventually have to replace the motherboard but you can keep using whatever your GPU/storage/other parts is. Sometimes that also means a RAM upgrade but it's still better than the literal nothing of modern Macs.