If by not doing much you mean: pays the monthly Medicare fee (what’s that, $165/month now?), covers medications, and picks up your share of the costs from appointments after medicares paid their portion, as well as providing vision/dental care and rides to medical appointments. Then sure. It does nothing.

Those onecare and senior plans also provide additional benefits, including a whole team of case managers, home care services, and non medical rides.

I’m not really sure what you mean by “isnt true insurance”. Masshealth picks up where Medicare stops. I’m not sure what your idea of having both would mean besides…one picking up where the other leaves off. Of course it’s supplemental, you can’t have two insurers paying the exact same portion of the same bill. That doesn’t mean you don’t have both insurances.