This can only be answered relatively. For an old geezer, I am in pretty good shape. Not able to run marathons, but at least can still walk unaided.
I drive anywhere I want to go, and can take care of my own needs independently. But I do have cleaning help, and enjoy a nap pretty much every afternoon. I can eat or drink whatever I want, but try to employ common sense about that.
In other words, "pretty good."
You are able to decipher how to run most electronic devices in everyday use. (For instance, can use your new cell phone without a panic alert to your grandchildren asking for help)