Raymond:
> Why do we care about this particular import?  It doesn't see slow in any way.

I ran a benchmark:

$ ./python -m perf command -o ref.json -v -- ./python -c 'import random'
$ # apply patch
$ ./python -m perf command -o patch.json -v -- ./python -c 'import random'
$ ./python -m perf compare_to ref.json patch.json 
Mean +- std dev: [ref] 13.8 ms +- 0.2 ms -> [patch] 11.8 ms +- 0.2 ms: 1.18x faster (-15%)

My PR 12728 makes Python startup 2 ms faster which I consider as quite significant on 13.8 ms.

I know that some users are fighting to get a faster Python startup. Mercurial is just one example ;-)