No doubt garageband is powerful and has decent capabilities.
But it has nothing to do with being on a mac vs being on a pc. The age old and pointless comparison to this day makes me laugh. Macs and pcs are almost equal and are when it comes to what they can both do. The advantage a pc has is that you can easily customize it and some things may not be compatible when you do install them where macs they must meet the standards set by the company so everything is guaranteed to work. Macs are more expensive and a pc is cheap to build so it all comes down to personal preferances.
But enough about that. This is a prime example of some of GBs capabilities either way.