Great question and some super points raised. Kudos to you Braille for being so active - kickboxing, upper body workouts, step, dance and pickleball - wow, awesome! You are certainly way more active than most people and should feel proud of yourself for regularly engaging in a variety of physical activities.
I am 65 and have a diagnosis of osteoporosis in my spine and osteopenia in my hip. I have looked into this area deeply and work with an endocrinologist who is great. In terms of osteopososis prevention there are
many things one can do - abstain from smoking, drink alcohol in moderation, eat foods rich in calcium (1200 mg/day) which is super important, take a calcium supplement along with Vitamin D if getting enough calcium from food sources is not realistic, wear a weighted vest while doing housework or when going for a walk, get in some balance training, do regular multi-directional impact movements (which you are getting with dance, pickleball, step and kickboxing), and doing resistance training. Yes, resistance training has been found to be helpful in addition to impact cardio movements. Here is a recent meta-analysis that you may find of interest...
The Effects of Exercise Intensity on Bone in Post-Menopausal Women
In the results summary the authors said, "Resistance training, potentially i
n combination with impact training, appears to be the most effective osteogenic stimulus at the spine and hip".
But resistance training is only one factor. Genetics play a significant role, especially if you have a parent who has had a stress fracture. You can look at your risk level through this science backed quiz...
Know Your Risk Quiz. (By the way, this is posted on the Osteoporosis Canada website which I recommend - the number one, national, go-to site in Canada that is full of useful, science backed info.)
All this to say that yes, ideally doing some resistance training for the lower body may have some protective effect. But, in my opinion, if you are doing all the other things right (nutrition, not smoking, impact movements, etc.) I wouldn't feel too guilty. If you really don't like it, it is unlikely you will stick to it every week for years just out of guilt. But if once in a while you can do a lower body workout with a fun friend, or go to a group class with a motivating instructor, or slip in lower body movements within total body workouts, metabolic workouts, or mat workouts (as others have suggested) then BONUS!, you can feel good about that.