Which specific properties are you referring to? (Because that does depend on the alloy composition)
Dynabook, Microsoft Surface (older ones), LG gram and HP Envy use magnesium alloy as well. “Feel plastic” is only a matter of the finishing choice.
I’m saying, what needs to be asked is “How to use a lighter material and yet have a premium feel?”…not just rule out the material choice altogether because of the finishing choices.