I know my grandma went 30 years putting off knee replacement then had it done in her 70's. She always regretted not getting it done sooner. Only saying if that is what it takes to get better, don't wait.
Right now just walking comfortably would be great. Yes, people I have talked with say got the knees replaced. Others have run afterward, but not like the ran prior. So if I can become "Joe Jogger" that will be a bonus.