It is premature. And furthermore, adoption will mostly be driven by new projects written in Rust, not conversion of C/C++. That takes time.

At the risk of dating myself, I suspect the author of that self-described rant either has forgotten how long it took for C++ to mostly dethrone plain C, and perhaps practically more relevantly, how painfully long it took for new versions of C++ to be widespread enough that people dared to rely on them. This stuff isn't easy at scale; adoption is slow.

Doesn't mean rust will ever grow like that, but merely slow adoption doesn't sound like a death knell by itself to me.