I must say I'm quite pleased to see how well Go version works. It does only use 1.5x the CPU and (predictably) much more RAM/VRAM, but not a crazy amount either (the expected increase is 2x).
Of course you can write a more optimal version in C / C++ / Zig / Rust, but at the same time Go is much easier to write and you don't pay for the convenience with an absurd performance loss like in Python or PHP
indeed, wal-g actually started as a port of wal-e which was Python: https://www.citusdata.com/blog/2017/08/18/introducing-wal-g-...
wal-g was a much larger improvement over wal-e. we're optimizing the margins here