I think that may the only job that could be safe for a given length of time. Eventually what you own will be superseded by something owned by someone else, and what you own will be worthless. If you are constantly investing in different products, markets and technologies you might stay ahead of it for a long time but that isn't what most people think of as a "safe job". I think what people are asking for in a "safe job" does not and will not exist.

But you can own a farm and take the dividends.

I don't know, taking dividends sounds like something very easy to automate. My piggy bank could do that.

More seriously, is being an owner even a job? If by job we mean "source of income", then the first big question is, is an economy sustainable if the only source of income for humans is ownership? (And probably redistribution, like a basic income guarantee.) My guess is yes, but I am not sure. (And the transition to this economy will be surely painful.) The second big question is, will the humans be happy about all their free time? My guess is yes, but I am even less sure.

The safest job, the only one safe job - is to be the owner.

Depends on what kind of society you expect. In a communist revolution, being owner brings you a bullet in head.

I don't know what kind of society will emerge when most people will not have jobs because of automation... a good long term strategy should investigate this too.