traditional web-oriented languages are dogshit slow and will incur huge costs both in hosting and performance mitigations

Also, for volunteer-run websites like Lemmy sites, costs are very important as hosting costs is essentially the whole cost, since the volunteers aren't paid.

For companies who pay devs a salary, the hosting is negligible compared to the engineer salary so it's more efficient to just scale up and spend less time optimizing.

I wouldn't recommend C or C++, even the NSA is asking people to stop using them in favor of memory safe languages. The equivalent in performance, is Rust.