Unmet needs in schools. A very large amount of children are anxious about school but it's always ignored, schools don't want to admit it, it's hidden unless you live it, covid has just highlighted what has been going on for years for many. Those who have pushed through now realise how much less anxious they are not being in school. I blame this on stupid Ofsted standards, focus on all the wrong things in education, lack of funding (less TAs for support where needed, teachers expected to do more and more, schools dodging acknowledging additional needs or children who just require that bit extra because they know it will cost them precious budget to support).
Better ID of MH health issues. We always get the old trope of 'everyone gets diagnosed with adhd, asd, etc etc these days'. We know more, times move on, these people have always been there but now they are actually acknowledged rather than suffering in silence.
Social media - increasing pressure to be perfect/be a certain way, less down time which is important for MH imo.
Families are pressured - gone are the days of a sahp for many. Parents are therefore more busy/stressed/anxious, less family time, less 1-1 time, everyone's tired after work/school/wrap around childcare, but it has to be done for many just to keep a roof over their head and food on the table. Also less involvement/help from other family as people move away, grandparents are still working etc.