Sound insulation in older homes is much better than in new. Thicker and heavier materials are much better at absorbing or reflecting sound, especially low frequency. Fire resistance seems to be a wash. I've seen the aftermath of new and old construction. We don't seem to have made improvements in this regard, but we have made the likelihood of them starting lower in all kinds of construction.

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.