Why not? What's stopping you?

Honestly, it's just too much of a hassle for me to be able to actually enjoy the running activity itself.

1. I have to prepare for the weather, organise proper clothes. Fine.

2. I sweat really hard. After a run I'm totally wet and I'd rather be indoors as little as possible, since sweat is dripping all over. And to get to a work shower I would have to go through an elevator and some other places. I'd feel people judging me if I'm sweating all over the place before getting to shower.

3. I'd prefer to not shower at work. I will have to also bring so much stuff along like changing clothes and must find a place to dry my sweaty clothes since they are dripping through. I must remember to not leave them there and I'm quite forgetful about things like that.

Depending on where your office is (typically some sort of city) this can actually be pretty dangerous (hit+run, crime, breathing very unhealthy air). Conversely if you work remotely, you can live in the suburbs or even somewhere more remote.

Additionally, I know in many in-person orgs leaving to go outside and smoke is super frowned upon and seen as a productivity drain. I assume "going for a quick run" would have the same effect at your off-the-shelf toxic org. In a remote org, no one is going to be breathing down your neck while you take 15 mins to go for a walk to collect your thoughts. Especially if we keep passing privacy legislation that limits the ability of the Amazons of the world to install spyware on worker machines.