It doesn't, CLion is way better.

What does it do better?

One problem I always had with VSCode, is that it seems to fill up its autocomplete suggestions with "near-string-matches" from files all over the project. The jetbrains tools are quite strict in that regard and won't propose random string matches that don't fit semantically.

That doesn't sound right. clangd should (and does) only suggest semantically valid suggestions. It's also much faster than the CLion's own C++ engine, though that might change with CLion Nova.

I used CLion before I switched to clangd + vscode and it was orders of magnitude slower.

CLion was what I used before and it was way clunkier than VSCode with clangd. Complicated libraries like CGAL just weren't usable for auto-complete, but were instant with clangd.