I know what you’re getting at, but generally homes are actually built that way.

Law enforcement can always go through any doors or windows if they have a warrant. You’d have to build a bunker to be save from them.

and then they break it and decide the cost of a repair isn’t worth it

Yep, that was me with my previous phone, which I did indeed have for over 5 years.

But there’s another major factor to it.

I use Android phones, which get official software updates for only a couple years (3 years for the most part). This includes security updates.

So when I got my current one it was one of only two I even considered, because only those two manufacturers promised 5 years of (security) updates at the time.

It has gotten better though, but except for Fairphone they’re still all very hard or impossible to repair.