I wonder if Zhaoxin's VIA heritage is helping them or holding them back - because of the patents, they were the only ones allowed to try, but since x86_64 and SSE2 are both now more than 20 years old, most of the patents don't matter any more (and AVX is not far from the cutoff).

The breakaway ARM China or SpacemiT or Loongson could drop in an x86_64 frontend and might get better results.