Uncertainty quantification and OOD detection in machine learning. It's on some people's radar, but has the potential to get ML adopted much more widely as people understand what it is actually really good at, and stop giving it things to do that it's bad at.

For a great recent example that get at some of this, see "Does Your Dermatology Classifier Know What It Doesn't Know? Detecting the Long-Tail of Unseen Conditions" - https://arxiv.org/abs/2104.03829

I'm not affiliated with this work but I am building a company in this area (because I'm excited). Company is in my profile.