senior travelers

I'd suggest doing a Google search for "Ireland tours for disabled travelers" and see what pops up.
As I recall, most of the tourist highlights in the major cities have been made user-friendly for those with disabilities, but attractions further afield in the rural areas not so much, though you can still enjoy most of the pretty scenery along Slea Head Drive and the Ring of Kerry from the comfort of a van or bus.
It may not be cheap, but given the high cost of rental cars at the moment a tour might be your more cost-effective option.

I don’t see a typical bus tour as a viable option for someone using a walker. I think you will need to travel independently and with careful planning.

What are your goals for a trip to Ireland? What are the places or activities that you dream of when you think of this trip?

One of my best friends just returned from Ireland. Her husband has advanced Parkinson. They had a fabulous trip.
They had a portable wheel chair that was checked and used the airline wheel chair to board and when departing.
They used Airbnb's for the 3 week trip. Some train travel, and also some car rental.

They booked some great day tours,including a fishing trip on the Irish sea.
I think part of the reason for the success in making it possible for a great trip was staying in Airbnb's, selected to accommodate his disability was key. Bedrooms on first floor for example.

Have a good friend that has Muscular Dystrophy. Their family travelled to italy & Greece a couple years ago. She used a travel scooter. Folds up in a bag, battery comes off. Worked really well for her. She could not do many steps so she stayed outside While Dad & daughter went in

edit: the travel scooter was carry on. Flight attendant stowed it IIRC

Thank you everyone will check these options out