Counter-example: tried to exercise, ended up doing more harm than good. Walking always made me barely able to move for a couple of days and continued trying, even once every few days, still hurt me, got worse, and I think it's responsible for how I am now (severe sciatic nerve damage).
That sounds like a disability and definitely is not normal. Far from a "counter-example", especially when the overwhelming evidence is that being sedentary IS harmful
I'm sorry that your experience has been crappy. And yes, not all strong exercises are great for everyone.
Still, there are advantages for not being sedentary and being active, as in light exercises does not have to disable you for days. You should look into that as it is not necessarily common.