[bicx]

You don’t have to exercise at all though. The far greater majority are people who don’t like exercise at all, and won’t do anything. To have a person do at least some exercise of any form is a big win for their health anytime it happens. That’s what we don’t want to discourage.

[weird-eye-issue]

Nobody is actively discouraging that so you are just making up a strawman argument. That said cross training is very important for things like injury prevention. So if you just do something like running and nothing else at some point you are far more likely than not to get injured to the point that you have to completely stop or switch to something lower impact like cycling. And while cycling is great it doesn't have lots of the benefits of something like strength training so things like your bone health could still rapidly deteriorate as you age. So that means something relatively preventable like a fall leading to a broken hip that you never recover from can still happen to you. But yeah just do what you like and make sure you don't do anything you don't like in the moment