Boniva (ibandronate) persists in the bone longer than Fosamax (alendronate). While that increases convenience, it has the disadvantage of increasing the possiblity of aytypical femur fracture and osteonecrosis of the jaw. Mind you, some individuals never develop, either. So that doesn't indicate that you are at risk.
Because of their persistence in the bone, bisphosphonates blunt the effect of the anabolic drugs that you eventually need, since medical opinion (now) is that you shouldn't stay on drugs that inhibit bone remodeling for more than five years.
Boniva was taken off the market in 2023, but ibandronate can be found as a generic. I think roche abandoned the drug, for the reason you mention -- it isn't capturing the market. And Roche was unable to hold onto the patent.
Your md may not have recommended more calcium because of the suspicion or controversy over whether it causes athersclerosis. I would worry for your friend because calcium and/or d supplementation can't reverse osteoporosis fast enough to prevent fractures. While some never fracture, vertebral fractures never heal in their original configuration. They alter the structure of you entire spine and worse, can cause unending pain.
Your point though is well taken. And, we often end up taking what our physicians recommend. I've seen a number of endocrinologist and one reumatologist, but never have been offered a prescription for Boniva or ibandronate.
I jumped into the more expensive injection, Forteo, because bisphosphonates are slow. They work by maintaining older bone that can't repair itself. The expensive, inconvenient injectibles build bone more quickly and build a structurally more flexible bone.
Wishing you the best.

Good evening @followheart87, Welcome to Connect. You asked a question about where you should start out for help with diagnosed osteoporosis. There are considerable options for someone just beginning to protect her/his bones from osteoporosis. If you have been diagnosed with osteoporosis, it is important to know what your Dexa scan revealed. If possible it would be good to have FRAX analysis that will indicate how likely you are to have osteoporosis issues within a 10 year time period. That can help determine the medication choices.
I did start with Boniva because I was already 75 years old and on a borderline osteopenia/osteoporosis margin. Unfortunately, I had serious reactions to Boniva and was transferred into the bone building arena with Tymlos. I had no reactions or side effects for two years of daily injections.
Then it was time to hold down my progress with Prolia. Unfortunately, again, I had serious reactions and was transferred to Alendronate (Fosamax) with the goal of holding everything in place. Fosamax is a once a week tablet. For me that works much better than the medications that are delivered by bi-annual or annual infusions. The half-life of those injections is quite long.
We are all different as you have noticed. Are you seeing an endocrinologist? That may be helpful. There is a also a great book available titled…Great Bones by Keith McCormick who also does consulting.
There are also insurance issues with a long preference for starting with the lower cost medications.
However, it is recommended that you start with one of the bone building options….Forteo, Tymlos or Evenity. After recovering bone stability it will then be time to select a medication like Prolia to hold everything in place, so to speak.
I hope that you have a chance to do some homework on your own. And if she is available, I would like to introduce you to @windyshores who can help you make the best choices.

May you be safe, protected and free of inner and harm.
Chris