This is a very good point OP.
And at what point are you going to consider yourself as having reached old age? I’m guessing from your post that you don’t want to reach mid 70s, like your parents and their friends with the horror stories, so how will this work? Will you get to late 60s and top yourself? What if you’re still in really good health, completely independent, you’re financially secure and you’re really enjoying your life? Are you sure you’ll be ready to give it up?
Or what if something happens to you next week? Nobody has a stroke or gets hit by a bus, until they do. What is your plan for avoiding the need for 24 hour care when, overnight, you can’t feed yourself?
Sort a pension out if you can afford to. Save if you can afford to. Sort out a will if you’ve got anything to leave. Organise power of attorney while you’ve still got your faculties (assuming you trust your children). Don’t hoard stuff. All of that is common sense and what we all should be doing where we can, but the rest of it sounds like a teenager who is horrified at the thought of ever being 25.
My mum is knocking on for late 70s now. She hasn’t got a pot to pee in so there’s nothing to organise, other than cancelling state pension payments etc. She will never be going in a home and will never be found on the floor 36 hours after having fallen over. But that is my choice and my plan, not hers.
I also do not have a pot to pee in and unfortunately I can’t imagine a scenario where I’ll reach a ripe old age. If DH should go before me, for any reason, my plan is to always have my phone with me so I can call an ambulance if I need to, and to keep my home as clean & tidy as possible so the neighbours don’t gossip when the Housing Association has to hire a skip to clear the place after I’m dead. And that’s it. There is nothing else I can realistically plan for.