There was a $10m prize announced yesterday for creating AI that can solve math at the Olympiad level. We still do not have a cure for most cancers, and there is little profit motive to do so, and this is in part an economics problem. Heck we cannot even guarantee that babies born today will be healthy, and this is partly rooted in economics and social science. So is the problem of mysterious pandemics, potentially bio engineered, and the class war it has ignited.
The world is far from perfect, and the list of hard open problems is huge.
> Even better: change the bounds of whats possible ;)
... which will be easier it you have a solid grasp of the foundations of the field. If you only ever focus on the "latest shiny" you'll be lost and left floundering when the landscape changes out from underneath you.