This is not true? OP has a lot of clinical experience, just because it's not volunteering doesn't mean its not clinical experience. MCAT is low so would recommend retaking if that's an option, but there are definitley some schools on their list that will still give them a shot.
Other impactful experiences recently replaced the disadvantaged essay. It's hard to say exactly what this change means but if you can right a compelling piece than feel free to do so. Most secondaries will have an "other things" essay or an adversity essay that you might be able to adapt something like this too, just keep this in mind and you can decide where is most appropriate for this.