"It’s well-known that all leading LLMs have had issues with bias—specifically, they historically have leaned left when it comes to debated political and social topics. This is due to the types of training data available on the internet." Perhaps. Or, maybe, "leaning left" by the standards of Zuck et al. is more in alignment with the global population. It's a simpler explanation.
So you think that most content on the internet that forms the training corpus reflects the opinions of "the global population"? Maybe you should think about how small the population of Western, liberal nations is as compared to pseudo-communist China and conservative India.