I think health problems are one type of problem that young people are facing, and the news has talked about mental health in particular being a growing problem for young people.

Lack of employment generally (not just health related) seems to be a problem - apparently the percentage of young people who aren’t in employment, education, or training is increasing.

I think Sir Gareth has identified some of the problems too. Lack of healthy role models, abundance of unhealthy role models. Abundance of porn, especially unhealthy porn. Negative effects of social media. Etc.