The Julia community is small and has no large commercial backers. Projects such as TF/PyTorch require community support and a lot of investment which Julia just doesn't have. In fact, Julia isn't even trying at the moment to "compete" with TF/PyTorch [1, 2].

[1] https://discourse.julialang.org/t/state-of-machine-learning-... [2] https://news.ycombinator.com/item?id=29682507