When you acknowledge that you have some “issues” in mobility, hearing, medical or just getting older, I strongly suggest you travel with another person. In my case, I am fortunate to a have a great husband who is most often my traveling partner. But I have traveled with a sibling, colleague or friend, someone who is aware of my limitations and is there to provide a helping hand (literally). Never assuming that my travel partner is willing and able to assist me when needed, I will directly ask the assistance question before we finalize any travel plans.
If you decide to travel with a group you cannot assume that someone in the group, the guide or another employee will be able to assist you. It might be a hand up into the bus once in a while, maybe, but not on any regular basis. The other people in the group will not be at your disposal if you need assistance. Luggage can also be an issue when you travel. A long time ago a veteran traveler told me that you only take as much luggage as you can handle by yourself.
Finding a person to be your traveling partner may be the biggest challenge but finding the right traveling partner can be lead to a great experience.