[ghaff]

>How come cars, homes, wholesome dinners, home repair, car repair costs more or about the same as 20-30 years ago

Cars primarily because cars today have a lot more "stuff" in them--in many cases, safety related. Although I'm not sure given improved reliability that the $/mile cost isn't less

I wouldn't be surprised if the cost of some fresh food has dropped but it's probably not a lot cheaper across the board. Mechanized farming has been around for a long time.

Home and car repair are largely a function of labor. There's relatively little benefit in either case to improved industrial processes. The process of building a house hasn't changed much and manufactured housing has never really taken off for a variety of reasons.