Phone Link is Microsoft’s late and closed source alternative to KDE Connect. It requires you sign in to a Microsoft Account for it to work.
This means all the transactions between your phone and your PC are monitored and sucked up by Microsoft.
The only unique (I think?) thing about phone link is that it enables you to use your Android phone camera as a webcam, which can be handy if you don’t have a quality webcam. I think its only in the beta version though.
I’m not sure if this is a Pixel feature or if its available across all of Android, but there is an option when you connect over USB to connect your phone as a webcam - but that is of course tethered instead of being wireless.