The opposing argument for much of their down-sides is the up-front cost of building a new home has it's own environmental and financial costs. Much of the down-sides to older homes can be retrofitted for substantially less cost and impact than a new home.
We could get the best of both worlds by designing homes for upgrades with large conduits for wirings, easier access to walls and attics, etc.
Why isn’t this more common? I’ve watched a few spray foam installations on youtube where they just spray directly over romex / wiring / cables .
Compare that with newer buildings I lived in, where I would be woken up at 3AM by my upstairs neighbor's cat running around.
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.
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.
Buildings a mere 50 years ago probably have very poor insulation (and hence high heating/cooling environmental + monetary costs), have electrics that aren't considered safe today, have plumbing probably containing lots of lead, and are lacking amenities considered standard today (electrical outlet next to the bed for phone charging, mixer taps, etc). Those buildings probably won't resist fire for long, and probably won't be suitable for heat pump heating. Sound insulation probably won't be good, so you probably get woken by your neighbour having sex.
All those things are fixable for a cost, or livable with a hit to quality of life, the environment, the house owners health, etc.
If we assume that the requirements for a home continue to evolve, then we can see that something built today would be unlikely well suited for use in 50 years. Considering that, perhaps it's best to build something easy to disassemble and rebuild 50 years from now.