Yes, I also suspect that at a certain scale it would make a difference, but with a single Postgres database and no advanced clustering or so, the real-life performance metrics of a medium sized Lemmy instance strongly point to Postgres being the bottleneck and not the Python or Rust codebase of the rest of the software.
That is, in theory. In practice, it can make a big difference. Source: Worked professionally with large services built in Python and Rust.
Yes, I also suspect that at a certain scale it would make a difference, but with a single Postgres database and no advanced clustering or so, the real-life performance metrics of a medium sized Lemmy instance strongly point to Postgres being the bottleneck and not the Python or Rust codebase of the rest of the software.