How much experience do you have teaching really elderly people how to work things?
Old people often lose significant cognitive capacity, and ability to learn new things. I have been through this with my folks. Things that seem obvious to you, like the difference between a DVD and a VHS tape, completely flummox them. They have much lower bandwidth than children and less ability to lay down new memories.
And credulity: In the years before my Dad died, a regular part of my visits was removing all the adware and crap that had accumulated on his browser, because he would click anything that said "click here." 20 years earlier he had been a software-writing scientist and nobody's fool, but his bullshit-detectors and underlying technical understanding had attenuated. There's a reason why a whole category of scams target old people.
So it's quite possible that the caring thing is not to get someone a computer.