This legacy package is a very simple authentication scaffolding built on the Bootstrap CSS framework. While it continues to work with the latest version of Laravel, you should consider using Laravel Breeze for new projects. Or, for something more robust, consider Laravel Jetstream.
Yes, if you're looking for something simple I'd go with Breeze, Jetstream seems to be more complex with more features that you might not be looking for.
- Downgrading laravel/ui (v3.2.0 => v3.0.0): Extracting archive this line is interesting.
Did you tried to install something before?, since it says it's downgrading to match the version 3.0.0 you specified in the command, that's why I bring it up.
Maybe you should type the command: composer require laravel/ui:^3.2.0 ?
If all fails remember you can always get Laravel breeze: https://github.com/laravel/breeze which is a more up to date version of this.