There is no doubt in my mind that new construction has the potential to be far better than old.
I have turned an 1800’s barn into living space, built a home from scratch 40 years ago, and just completed a retirement home for myself and my wife.
The last project benefits from the advances in technology and efficiency using a 95% boiler for radiant heat and a 24 SEER heat pump for AC and spring and fall heat. Insulation is R50 in the ceiling and R28 in the walls. Modern doors and windows that seal up tight. An Energy Recovery ventilation system that maintains a positive pressure when burning a fire, or running appliances that vent to the outside. All recessed LED lighting, etc.
None of which is going to be native to an old house.
That’s not to say that you can’t cut corners in construction, either old or new, but if you want to do things right, new is the clear winner if you want to capitalize on what’s available.