Portable wearable air conditioning and sun protection, that's what you'd need to make it comfortable. Maybe like a robotic exoskeleton, we can't be far from making that affordable.
Also I would love to see more covered bikeways.
A bicycle on flat asphalt is more efficient than a person despite person+bike moving more total mass; but still the cost of mining iron ore, making steel, making a bike for every customer, compared to just building the store and the homes close enough to walk and not doing any of that…
Energy.gov says “In 2021, 52% of all trips, including all modes of transportation, were less than three miles, with 28% of trips less than one mile”, it’s daft either way that people want to use a car for such short distances or that urban spaces are designed so that things are relatively very close but juuuust too far for convenience.