Honest answer? The biggest thing you as an individual can do to combat the mental health crisis is to help plan, create, and maintain social groups and spaces.

I'm over telling people to check on each others' mental health (as the primary intervention) because it leads to a hyperfixation on mental health symptomology. It also minimizes the importance of loose acquaintences to mental health; people who you can absolutely have plenty of casual social interaction with, but who you're not actually close enough to talk to all that intimately with.

TLDR; you should absolutely still check on your friends, but the best thing you can do is host more weed-free and alcohol-free parties and other casual in-person gatherings for your social and hobby groups (substances can be ok and fun, but a looot of people really need more gatherings away from them). Social isolation is on the rise and just telling everyone to constantly trauma dump has NOT been helping.