Sunlight can definitely clear up some skin conditions like eczema. I don't know about making skin healthier in general though. It 100% causes aging in skin though so any "healthier" skin you get will be totally wiped out by the wrinkly mess it becomes in your 40s.
The message we should send kids is not "wear suncream; it prevents cancer" it's "wear suncream; it prevents wrinkles". Surprising how many people don't even know that.
There's a famous photo that demonstrates it very obviously:
What else do you think it could be caused by? The sun is the obvious explanation and we know the sun damages skin.
Another easy source of proof is women's skin damage patterns. Look at any old woman's naked body (if you dare) and their face, and frequently upper chest will be much more damaged than the rest of their body which has been covered by clothes their entire life.
The message we should send kids is not "wear suncream; it prevents cancer" it's "wear suncream; it prevents wrinkles". Surprising how many people don't even know that.
There's a famous photo that demonstrates it very obviously:
https://metro.co.uk/2018/01/28/photo-truck-driver-shows-28-y...
Which side would you prefer?