Yep i also wash the car myself, takes 4 hours all in, but don’t do it to impress others, I do it for myself, to ensure it remains as swirl free, and scratch free as possible, and to make sure the paint work doesn’t get dull.
In my mid 50s now, so yes it is becoming a touch harder, but still worth it once done, and as others have said, I also find it very therapeutic.
Ideally would like to wash it every two weeks, but with a full time job, sometimes it can be once a month.