This was actually intentional.
Reasoning:

• only yarn/npm i command failed for some reason
• everything else is processed and copied.
• yarn install can be run/debugged manually
• exiting early will skip creating the swanky.config, so the project will be useless and the whole process should be reverted (delete the folder)

As I see it there are 2 options:

• delete everything and fail/abort
• finish instantiating the project and notify the user to run yarn on their own

I see,
When node version is low (e.g. 16.x.x), install dependency process fails. it is good to warn finishing installation by using yarm/npm.
I close PR for now