> Let me know if I am still using it wrong.

You're not using it wrong, but you are measuring wrong.

Check out the filetype of the journal files

  $ file -bi /var/log/journal/1234blahblah/system@foobardedoopdedo.journal
  application/x-linux-journal; charset=binary

Your measurement procedure is wrong because the `journalctl` command is doing something different. It isn't just reading a plain file, it is reading a binary file. On the other hand, `grep` and `rg` are reading straight text.

  > it seems difficult to believe that journalctl --grep can be faster.

Why? It could be doing it in parallel. One thread starts reading at position 0 and reads till N, another starts at N+1 and reads to 2N, etc. That's a much faster read operation. But I'm guessing and have no idea if this is what is actually being done or not.

P.S.: I know. As I specified in my earlier comment, I get burned with build artifacts and project logs. Things that most people would have in their .gitignore files but you can sure expect to grep through when debugging.