Some data in support of @soraminazuki (who makes good points throughout this thread) on an i7-1370P linux laptop running Linux 6.15.7: $ tim 'bash -lic log

Some data in support of @soraminazuki (who makes good points throughout this thread) on an i7-1370P linux laptop running Linux 6.15.7: $ tim 'bash -lic logout' 'zsh -lic logout' 55.3 +- 3.7 μs (AlreadySubtracted)Overhead 7454 +- 26 μs bash -lic logout 7934 +- 39 μs zsh -lic logout (Using https://github.com/c-blake/bu/blob/main/doc/tim.md https://github.com/c-blake/bu/blob/main/doc/tim.md) About 20,000 entries in the Zsh history slowing it a little. All completion activated (but zcompile'd, along with a very large digraphs.zwc). I think most would not be troubled by taking 1.06X longer, though, especially at this 8 ms scale and for interactive session initiation. Note this test upper bounds Time To First Prompt { a different "TTFP" from Time To First Plot ;-) }, since it also exits as part of the `-c`.