Yep. That's what Macs don't offer. The ability to upgrade the guts of your computer, piece by piece.
The PC on which I am composing this reply is: a no-name beige box from about 2000, with an ASUS mobo, Intel Duo, and RAM from 2007, three SATA drives from 2009, a DVD burner from 2003 or so, a vintage 1990 IBM clickety keyboard, and one of my (dwindling) stock of Logitech Trackman trackballs.
It’s admirable that you are able to do that. But most people don’t have the technical knowledge to build a computer from the ground up.
Most folks want things to work from day one. The Mac does that very well indeed.
Not exactly true. It's really not a problem to upgrade the hard disk in a Mac.
I’ve upgraded the ram & hard drive in my 2006 Macbook a couple of times without issue. Replaced a fan as well. All of it done at my kitchen table with zero issues.
I’ve upgraded the ram x2 on my 2009 Mac Mini & upgraded the HD easily on a device Apple itself claims is a “closed system”. If you can read and follow directions, Mac products are easy to upgrade RAM & HD’s.