Going to the office meant a baseline of 7,000 steps a day, plus quite a few flights of stairs. Plus it was easy to go to salsa and gym after work (because I was already out of the house, so it was easier to to talk myself into going).
I struggle to do any of those things when i'm remote. I know perfectly well that I physically can, but that psychological inertia is extremely powerful.
A close analogy might be weight loss: "nothing" is stopping anyone from eating less, yet most Americans eat more than they should.