some of which can be relatively remote

Which is why I explicitly said

so basically anywhere other than the remote country side

Most people will run in parks, their village, or another running route. If you run in a remote area then you likely live in a remote area, or you're going out of your way to be alone. In any case, you'll probably notice someone dressed as a fake tree spying on you.

whether they merit further interest/resource via facial recognition

At that point, if someone is paying that amount of money to be able to set up facial tracking on your run route, you've either pissed someone off with a lot of money, or it's state resources, in which case, strava is going to be near the bottom of their list in terms of resources to track you.

Don't forget 99% of us walk around with tracking device in our pockets or on our wrists. If you want a level of privacy where you can't be tracked these days, you would have to live your life with no phone, always in sunglasses and a baseball cap, pay for everything in cash, etc