You can pay the greenie winnie tax and go full passive house and be completely off grid sitting pretty in an airtight optimally efficient home: https://www.youtube.com/watch?v=fhbLjEKKLVM
It would also triple the construction cost of the house. Reasons. But hey, $0 energy bill.
Most builders don't do any of that stuff, like at all. Just the bare minimum required. They aren't incentivized. Most consumers would - and do - opt for single pane windows over dual, and dual over triple, 'etc. Even when the windows would "pay for themselves" over their lifetime.
It would also triple the construction cost of the house. Reasons. But hey, $0 energy bill.
Most builders don't do any of that stuff, like at all. Just the bare minimum required. They aren't incentivized. Most consumers would - and do - opt for single pane windows over dual, and dual over triple, 'etc. Even when the windows would "pay for themselves" over their lifetime.