This is partly due to Dolby Atmos (and all formats > 5.1 channel) placing vocals in the center speaker as opposed to it coming from equal split between left and right stereo speakers, and so it can create the impression the audio is directly in front of you rather than in the “middle” which your ears are calculating because right and left ears are hearing left and right speaker simultaneously. 5.1 and Atmos are more realistic because in the real world when someone is speaking or singing (unamplified) they’re directly in front of you, not to the right and left of your ears simultaneously. The funny thing is thanks to stereo/live music we’ve gotten used to listening to vocals incorrectly for decades if you think about it, with the singer or speaker being a “mono” source that is then sent to left/right speakers which you hear as a fake mono signal. That’s why in film 5.1 mixes dialog is usually placed in the center channel if the character is in the center of the screen, with room reverb on the voice being sent to left/right/left surround/right surround and height (in the case of Atmos) so you’re given a much more naturalistic sense of spatialization. So this will make any musical track you’ve been used to hearing in stereo that has been remixed for 5.1/Atmos sound like the vocals are “front biased”, because in fact they ARE front center biased.
