Binary-trees is just an exceptional case for Go (and an unnatural/unusual program to boot). If you look into the paper (https://greenlab.di.uminho.pt/wp-content/uploads/2017/10/sle..., page 261, Figure 2, bottom left chart), you'll see a different benchmark yielding much better results relative to other languages. You'll find overall results on page 263 in Table 4 which aggregates 27 different benchmarks. There you see that time-wise, Go is roughly comparable to Pascal or C#.

Runtime footprint and CPU is pretty tiny for Go. It’s shockingly low cost to run it. I am frequently surprised.