it's sad to think that we will all be attended to by machines in old age,

I suppose it is sadder to think of neglected dogs and so the Homie is a safer bet.
I guess the point is that the Homie equally inspires the old person to feel young at heart as might otherwise a pet dog. One might have to worry that they will be so full of energy that they will be asking for a real dog next! And throwing parties for all their rediscovered loved-ones and friendly neighbours and kindly carers.

Another consideration why the Homie is ideal could be that a happier old fogie makes for an easier object to care for. Try putting a toddler to bed with the Cuddly lost in some gutter somewhere....

One might be persuaded to worry a little about the Homie though, at a certain stage, in specific instances, (when in the care of a temperamental, mentally volatile person).... I mean it's not like they don't have feelings...
Look at these ones and weep:

lost – toy bunny

"Forgotten Love".