I recall twenty+ years ago while watching Gundam or Armored Trooper Votoms having a discussion with people who all generally seemed to agree that while mecha were cool, the reality was that no one would ever find a way to make humanoid war machines practical.
While I think it's still reasonable to say that a aerodynamic transforming mecha jet in space makes less sense when it has a pilot vs. being autonomous, this video below has now convinced me that mecha are not only in the future, but likely:
I mean....holy cow. Now imagine that guy with a seriously reinforced titanium carbon frame and thirty feet tall. Consider me.....fascinated and terrified all at once! If this sort of robotic engineering gets cheap and efficient, I predict a battlefield full of terrifying mecha killbots in twenty years or less.