What would you like your brother to do and have you discussed this with him?
When our Mum was alive and frail, my sibling did most of the "helping". Mum lived alone in accommodation that had pull cords to call for help, key boxes outside and such.
But my sibling did all Mums shopping, visited her for an hour or so most days, Mum always had Sunday lunch with sibling and family.
I visited, with my adult child, once a week for a couple of hours.
I worked full time (up at 5:30am home by 7:00pm) lived 25 miles away and didn't have my own car. I was also a single parent albeit child was an adult by then.
Sibling lived round the corner from Mum and worked part time. Both of us had adult children by the time Mum got frail, though my sibling had a reliable partner.
I dealt with Mums paper work (claiming Attendance Allowance, paying her contribution to the carers that she needed etc) but that really was not on a par with what my sibling did. What Mum needed most in her life was company, and my sibling provided that in spades.
But short of moving house and giving up my job (Mum lived in a small village with very poor public transport) what else could I do?
I was and am (though Mum has been dead for over 15 years no) grateful to my sibling for what they did.
So what is it you want your sibling to do?