Interesting. The tests use Python 3.6, which on my system replicates the huge difference shown in startup time using and not using `-S`. From 3.7 onwards, it makes a much smaller percentage change. There's also a noticeable difference the first time; I guess because of Linux caching various things. (That effect is much bigger with Rust executables, such as uv, in my testing.)

Anyway, your analysis of causes reads like something AI generated and pasted in. It's awkward in the context of the rest of your post, and 2 of the 3 points are clearly irrelevant to a "hello world" benchmark.