The great exceptions to old homes, are those built by contractors or good architects (with good contractor relationships) for themselves. They will often engage in overkill with foundations, material and workmanship. I don't want to identify such homes I have appraised. An old Craftsman home in Fairfax comes to mind. Build by a famous contractor for his family around the turn of the century. His nameplate is still on the house. They knew where to place the homes - on hillsides or knolls with bedrock. Look into the gigantic crawlspaces and see exposed bedrock. The timber is redwood, 2x6, 6x6 construction. Looking in the crawlspace, the timber looks clean and untreated after all this time (100+ years).
In these homes that I discover which were built by contractors for themselves, I can sense solid construction - compared to surrounding homes, from appearances alone. But there are many clues.
I even appraised one such in Pacifica, a rancher built in the early 1990's and was able to talk to the contractor about the construction after he sold it moved up further north. Massive foundations. And, this was for court. A divorce. Another appraiser in the area had appraised for the opposing party. The other appraiser did not take into consideration the quality of construction; and one can argue most buyers wouldn't notice. An engineer would notice. - It was a rancher - and unless you had a keen eye you wouldn't notice the difference. Flat sides, straight orthogonal cuts, perfect.
Of course if you don't take care of even these high quality homes, they will age. The owner has to stay on top of maintenance. That takes money and/or other resources such as skill and time.
When I built the 1800 sf extension to my home in the 1990's, I dug the foundation myself, until I hit bedrock. I was lucky, much of area is built on sand and is subject to liquifaction - according to the maps. But bedrock juts up under the center of my property. The foundation poured was massive. - Mostly because I did not know better. Most experienced contractors would probably have used about 30% of the concrete I used. But so much the better. We'll have to wait for the next big earthquake to see how robust it is.
My dad was an excellent cabinet maker and carpenter, so I grew up with construction and know probably quite a bit more than most appraisers.