Is this some sort of weird gotcha or are you sincere?
Joint damage is not really statistically correlated with long distance running, and anyone targeting a sub 20 minute 5k is going to have their weight and form so dialed in, it probably is barely a risk at all.
I never progressed past 30km from hearing all of these people quiting to save their knees. I wondering where that sentiment comes from if there is no correlation.
My understanding is that people destroy their knees in many ways over the course of their lives and that running makes that painfully obvious to them so they stop.
I think its related to weight. We have to acknowledge that there is a serious obesity epidemic in the developed world. The majority of adults are overweight and obese.
This is anecdata from what I've seen: you see fat runners. you see old runners. You dont tend to see many fat old runners.
The other thing is that if you dont regularly change your running shoes, you will absolutely hurt yourself. I get knee pain if I don't swap out my shoes every 250 miles or 3 months.
My view, on top of what my sibling comment said, is that even if joint damage was a risk ( and it shouldn't be because I'm doing strength training with weights under a certified coach to prevent stress from going to where it shouldn't be), I'd rather take that risk than be sedentary, fat, and at home all the time like I was before I started running. I found a community on top of an activity I like. I found that I have goals beyond just my career goals. I got into coooking and baking because nutrition is important for an athletic lifestyle.
Joint damage is not really statistically correlated with long distance running, and anyone targeting a sub 20 minute 5k is going to have their weight and form so dialed in, it probably is barely a risk at all.