That is complicated, but also not related to the 5th amendment. Warrants are a part of 4th amendment rights.
The 4th amendment is intended to ensure (among other things) that the government can't search some locations for evidence without first proving they have a good cause for that search.
The 5th amendment is intended to ensure (among other things) that the government can't use force or threats to make you admit to a crime, regardless of if you committed or didn't commit that crime.
The distinction is that a court could grant the right to force someone to put their thumb on a phone, or look at a phone's camera, but they (in some but not all cases) cannot force you to type in your passcode.
The argument is that your fingerprint or face is not "testimony" but a fact of who you are, but your passcode is a testimony, a declaration that you have some specific knowledge.
A phone unlocking is equivalent to it saying "Yes that is my owner/user", and that is not that person testifying, it is the device testifying against that person. Similarly it would be as if someone kept a picture of them committing a crime that was found with a valid warrant, they could not claim that having taken the picture it is their own testimony and can't be used against them. Taking the picture is a past event and requires no compelling of testimony to be used as evidence.
Getting biometrics without a warrant is a contentious issue. There are situations where a warrant is not needed, and these have also been abused to gather biometrics in situations that should have required a warrant but it was denied.