When I was younger, I was so bad about using sun protection and hand cream on my hands. They were the first thing to show ageing, followed closely by my neck (which I also did not protect from the sun). If I had used sunscreen I am sure they would have looked better by now.
I do have some liver spots but not as many as some people I know. I had them removed once but they do come back if you are out in the sun and not fully protected. I washed my hands so much during covid and did not re-apply sunscreen so that did not do good either.