Well, most people who experience elder abuse do have children. Having them isn't a failsafe against that; we are all vulnerable to it unless our children are our only carers, and how many people does that apply to? Take heart; most carers and care facilities are fine, especially now that there can be cameras everywhere.
I am really, really sorry that you didn't have children when you had wanted them. That is tough. If it helps, during my forties I saw a veritable epidemic of my peers having very little time for their parents and hardly bothering with them at all even when they were sick and dying. I have been really shocked at how my generation (mid-Gen X) treat their parents.
Partly I'm lonely because my job became permanently remote during the pandemic and partly it's because I'm still recovering after losing my dad after three years of upheaval. So I'm a bit depressed. But I do believe that people without children have the time to make meaningful connections, often via groups and community volunteering, and that there is no reason to be lonely in later life. Many retired people don't see much of their children and grandchildren.
I mean, logically we should be LESS lonely than people with children because we have more time to build connections! The trouble with putting everything into your family is that children grow up and leave home...someone on here recently made a comment about how a single woman she knew wanted to be friends and see her at weekends, but the poster said she couldn't spare any time for her at weekends at all, ever, basically. I thought that was a bit smug and short-sighted. Kids grow up, spouses can die or leave you. I thought it was a pity she decided that she had no time for someone because they were single. Surely she could have seen her on the occasional weekend or invited her over to join in with a family meal. I think it's that kind of attitude that can leave people feeling a bit lonely when their kids have left home, especially if something happens to their marriage.