I think it would be easier to go after someone’s Apple ID. If you can log into the Apple ID, And their data is backed up on the cloud, You have access to pretty much everything. It’s just the stuff downloaded onto the hard drive that you would not see. Otherwise removing and backing up the hard drive to an external hard drive would be the easiest way, But you actually just need to take apart the computer and plug in the hard drive to a backup device, You would not actually need the password for the Lock Screen. Apple security is basically meant to prevent attacks from stupid gangbanger types that stole someone’s computer to sell for a quick buck. Trust me bro is a much more effective attack for actually getting someone’s data. But good luck taking apart and re assembling someone’s MacBook in 10 minutes without it looking tampered with.