A Dyson Sphere Would Be What an Advanced Alien Species Bestows Upon its Retarded, but Benevolent Steward. Not Something A Species Would Create For Itself, if It Had Any Interstellar Mobilization. It Could Just Be It’s Impossible To Leave the Solar System. But Dyson Spheres are Not Efficient or Realistic. If You’re going to Travel to Other Stars, You Have to Break the Laws of Thermodynamics as They’re Currently Understood.