I can replace the keyboard in my Thinkpad myself. Who apart from Apple can replace the (flawed) keyboard in new the MacBook Pro?

That may make it inconvenient for you but it isn't necessarily an environmental problem. Most people don't take their hardware apart, they take it back to the store.

It becomes an environmental problem when Apple stop offering to fix it, or make the cost of repair uneconomical. I can still buy a replacement keyboard for a 20 year old Thinkpad for ten dollars and pay someone to install it.

Granted, there are some aspects of Apple hardware that can still be repaired/replaced by third-parties, but their trend is away from this.

I have a fifteen year old iMac on my desk right now.

That's great! But it's unlikely that today's MacBook Pro will last anywhere near 15 years.

That's apple's and oranges. Laptops move a lot, which opens them up to damage. I fully suspect an iMac to last 15 years.

I have a first revision intel macbook pro from 2006 that still works just the same as it always have.

not quite 15 years though, so I guess OP is right...

Better not buy a new high-end car built after 2010 or so then. You should see how difficult they make it to work on them.