I have to say that this is a rather rose-tinted picture of various investments:
Rolls-Royce went bust in 1971 and spent a more than a decade in state ownership!
Investment Trusts: your sample suffers from survivorship bias- have you researched the other investment trusts that were around in 1868 or 1888 or 1909 or 1929? I don't have the resources to do that but I bet there were more than a dozen others around at those dates.
Family companies: some survive some dont- it was only a few years ago that Sainsbury nearly lost its independence. Cadbury is no more. Clarks were in a near in fatal miss and survived only through traumatic restructuring about a decade ago. I am impressed that Warburton's are in the 5th generation but this is surely a very rare exception.
As you might have guessed I do not agree that you can lock up your assets in one investment and assume it will last forever or even a hundred years. Decisions will have to be made to change your portfolio. Some decisions will be better than others.
regards and good luck