One of my biggest points of criticism of Python is its slow cold start time. I especially notice this when I use it as a scripting language for CLIs. The startup time of a simple .py script can easily be in the 100 to 300 ms range, whereas a C, Rust, or Go program with the same functionality can start in under 10 ms. This becomes even more frustrating when piping several scripts together, because the accumulated startup latency adds up quickly.
Big packages shouldn’t be imported until the cli has been parsed, and handed off to main. There’s been work to do this automatically, but it’s good hygiene to avoid it anyway.
A modern machine shouldn’t take this long, so likely something big is being imported unnecessarily at startup. If the big package itself is the issue, file it on their tracker.
Note that if you're that far behind on a project, the rational choice is to significantly cut its scope, and push the rest to the following releases.