1) Food is a basic necessity; then, there’s the flavour of home-grown fruit & veg.
2) Home growing is crucial to reducing environmental impact: a well-organised garden safely recycles water and pretty much all other waste, plastics excepted. And a house with a large garden which for now still needs heating can sustainably produce some fuel by means of pruning and/or coppicing.
3) Working in a wildlife-attracting garden improves mental health, and the fellowship of like-minded gardeners is constantly rewarding.
4) One can solve many a knotty problem whilst gardening or walking.