Per upstream's currently supported platforms [1]: PowerPC (64-bit) is tier3: Julia may or may not build. If it does, it is unlikely to pass tests. Binaries may be available in some cases. When they are, they should be considered experimental. Ongoing support is dependent on community efforts.
I have requested removal of ppc64el binaries in #956522. [1] https://julialang.org/downloads/#currently_supported_platforms