Are there any startups using tech to address these current problems? I'm specifically interested in problems like housing refugees from Afghanistan, or hurricane disaster relief in Louisiana (but there are of course, many other important problems).
Consider covid-19: Apple and Google rolled out these contact tracing apps in pretty record time. And yet, they had virtual no impact on the actual epidemic. However, there's still a ton of tech being used to fight it. It's just the tech being used isn't from large tech companies that swooped in, it's from people who have been doing this for years before the pandemic and will probably continue doing it for years after. None of this diminishes the need for tech people to help on these causes; you're probably going to be better able to have an impact working within the orgs doing the work, rather than a startup or tech company trying to sell to those orgs.
Alternatively, consider looking up resources on "Effective Altruism" -- one direction that could take you is that your ability to improve the world may be to just make as much money as possible and to donate it directly to those most in need.