Sure, the [carbon] accounting looks a little different if you're having to pull out most of the load-bearing walls to accommodate a change of use and underpin to build on top or considering replacing old masonry with something built to maximise energy efficiency. But rebuilding entire houses to keep up with the latest fads in mobile charge ports and mixer taps is about as good for the environment as "fast fashion"!
This must be regional. In the PNW we'd never knock something down for that. Stripping the drywall out and redoing the plumbing/electrical/insulation is quite a lot less expensive than putting up a whole new structure.
This has never been my experience. I've done a lot of this kind of work, in several different cities (all US though).
A full rip & replace of plumbing, electrical, and roofing should cost about 20%, and require about 10% of the time, compared to building new.
Plumbing should last 50 years (rough plumbing -- fixtures are decorative and usually change with taste before failure). Electrical should last longer, but systems older than 1970s probably need updating. Roof should last 25-30 years depending on style/material.
The problem lies in a homeowner who doesn't have much spare cash - so they rewire one year... and then a few years later they replumb... and then a few years later they replace the roof... etc.
Overall, they spent more, but in small increments so it didn't feel like more.
Typically regulations allow things to be 'grandfathered' - so renovating a house allows you to avoid getting permission to rebuild, which may be denied.