It's not maximalist. It's reality.

If you want to be healthy, you need to put in serious work. 10 minutes walks won't cut it. Sorry that busts your bubble or whatever.

You are trying to say anything is better than nothing, and then using that as some sort of 'just do the bare minimum'.

The cardiologist association recommendation is 150 minutes a week of medium intensity, or 75 high intensity minutes. That's 5 days of hard work for 15m at threshold, or 5 days a week of 30m of aerobic intensity. That's zone 3 or higher, which is you can feel your heart pounding and you are sweating sweating.

a casual bike ride isn't aerobic activity, it's zone 1-2. a walk is zone 1, it's slightly above resting.