It's some work, but not hard to solve technically having been at companies that deal with very similar problems. The main difficulty is less technical and more investment needed vs value + investment is partly outside of the modeling engineers making the system. Part of the improvement can be done by classical computer vision techniques. But mixing classical computer vision techniques with modern ones both feels somewhat like a hack and complicates the system. The other big area though is dataset improvement. Engineers building ml systems and the people collecting and organizing the needed datasets are normally different people with mild connections to each other. For companies that rely mostly on existing datasets and finetune from them, having to add a data curation process is a big pain point. Most companies have immature data curation processes. Many of the popular open source ml datasets have poor racial diversity. The most popular face generation dataset is celebA, full of celebrities (mostly white ones).

Other issue is for many of these systems having a racial bias in the error rate has mild business impact which makes it harder to prioritize in fixing. Last issue the work needed to fix this tends to be less interesting than most of the other work to make the system.

So overall, the main issues are lack of good open source fair datasets with loose licensing, cross organizational need to solve it (engineers can not code up a fair dataset), and business prioritization.

edit: Also solve here is getting accuracy across races to be close not zero. ML models will always have an error rate and if your goal is 0 errors related to racial factors that is extremely hard. Modeling is about making estimates of data not knowing the truth of that data.

Overfitting is also a technically easy problem to solve, but high profile cases in which it's not solved with obvious negative consequences could also lead to investigative journalism.

The short answer to your question is the same as the one to a lot of programming questions: It's not a technical problem, it's a people problem. Just getting the industry to recognize and acknowledge bias took investigative reporting. The prime example really is the situation with social media and targeted advertising algorithms. We still have people, influential people, like Mark Zuckerberg going around saying that ML isn't really a problem, everything's fine, social media isn't playing any role in destabilizing democracy, targeted ads aren't a threat to anyone's safety, and neither of them have anything to do with the breathtaking levels of economic equality we see.

No doubt there are still plenty of other issues with ML that haven't (yet) made it to popular attention, and the people employing it aren't making decisions based on social value or common good, but simply invoking free markets and capitalism as their guiding philosophies.