I really don't understand why the 'armour' gets questioned - sure, I prefer it being 'just cloth' but the Pre-COIE suit was indestructible (and stretchy, but we'll leave that for now), but no one seems to question that Superman's invulnerability...
My, personal, criticism of the 'armour' is of the 'bulky' look it has been depicted in, and that it's actually called (ceremonial) 'armour'* - it's basically a Kryptonian version of a tuxedo, or a sherwani...and that the other (main) heroes have a similar (unified) look with the armour lines...
Bookmarks