Like Boldly, I also think it's better to walk a dog daily, except in very extreme weather conditions. It's slightly different for say working dogs - my friend's farm dogs don't get a "walk" as such, but they are busy all day.
BGf, you are very lucky that you have a healthy adult dog with good behaviours and no grooming needs. When your dog becomes older, things may change.
We have three greyhounds, rightly considered as a low input breed. However, we do groom them regularly (not every day) and they also have baths occasionally. In addition, there are daily walks, runs with DH, training classes from time to time. One is v elderly - she has been having weekly hydrotherapy (factor in time and expense of this, driving to and from appts). Now she's had a stroke - we have to spend a long time each day feeding her and clearing up afterwards (both her and the kitchen
). Different meds morning and evening, to be cunningly inserted into a food of choice so she'll eat them. She has regular vet visits (more time and expense). The other two are wormed and de-flead regularly, have annual boosters and nail clips at vet. Don't forget the extra housekeeping - even short haired dogs do leave hair everywhere, track in muddy paw prints, leave poo in hte garden that needs picking up, extra laundry for dog beds and blankets etc etc. We feed raw so there is some extra time spent there on preparation and cleaning (not much). The old girl had an accident in the night so that needed cleanin up when I got up this morning. None of this is particularly time consuming by itself but taken together it really adds up, especially when I remember the ease of housekeeping before dogs (we don't have DC).
We often see threads on here about the joys of puppy hood (weeing, chewing etc) but we don't see so much about the other end of the story, when people have elderly dogs, yet eventually many of us will have older dogs that will (like older humans) need extra care even when they are still enjoying a good quality of life. It's right we should be sharing this with prospective dog owners.
It really upsets me when we see threads like the one on here at the moment where people are wanting to dump a dog after it started having continence problems.