Folks of a more mature age are generally given higher a1c targets to meet due to the level of action needed to take to reduce it vs quality of life vs long term benefit. The target would be something to discuss with your doctor.
Metformin can be beneficial and its not like oh hey, I can eat what I like with no impact on bg but it might just give you some wiggle room to loosen the reins a little (just don't let them go). (its designed to be in combination with a healthy diet).
I actually know plenty of people who are T2, take metformin and get on business as usual without making huge changes to their diet apart from cutting out a lot of the excess sugars (like in tea and coffee, fizzy non diet drinks, excess treats etc). No massive carb changes done at all. Everyone is individual as to what works and what path people choose to maintain control of their blood glucose levels.
Metformin can lessen the risks of some other things such as stroke, dementia and heart problems and more which may be of benefit to you.
Unfortunately, there are some side effects associated with it (mostly tummy/digestive) but you shouldn't be put off trying it at least if that is the path you choose to take.
My personal opinion would be to try metformin if it is on offer and be sensible vs super strict. If it all goes too far out of control, dial it back in a little bit if it imposes health concerns or puts your hba1c too high.
Enjoy life and eat more marmite
(I'm in the love it camp)
