I don't understand what are the consequences of using the command option --prefer-offline in npm ci. From the documentation (v8, current release as of writing this question):
prefer-offline
Default: false
Type: Boolean
If true, staleness checks for cached data will be bypassed, but missing data will be requested from the server. To force full offline mode, use --offline.
I still don't know what are the consequences of doing that, especially when using npm ci instead of npm install.
Staleness checks will be bypassed, so I will get old package data from cache? Why would I care about that, if the version is already fixed in the package lock file, so I cannot get new version of the package anyway?