Not really apples to apples. When the MacBook Air was introduced, it was barely a viable consumer product and you had to pay a premium to get a taste of the future. The yields for low power consumption chips improved dramatically over time and the prices dropped considerably. Economies of scale allowed the MBA to move down the product line while still providing a better product over time.
If Apple released a 27in 2560x1440 native resolution display without 99% P3 coverage and only 375nt brightness in 2022, sure it could likely hit a well-under $999 price point. Apple doesn’t want to be in that market. All of their displays on phones, tablets, laptops, and displays are capable of 2x or 3x “retina” now. That’s not economies of scale allowing the display to get cheaper while improving over time. That is a product that gets cheaper as it gets worse comparative to technology of the day.
A 5K display with the general features of the Studio Display has never existed for less than $1299 MSRP. I don’t know why anyone would have a realistic hope for it to be under $999 given the market and knowing that Apple is going to use better materials to house the display than competitors. The only way they’re making that product is by repackaging the M1 iMac display…a display that is only 24 inches and 4.5K resolution. I hope they make that product though. It would be great for the growing number of people who can legitimately use M-series laptops as desktop-laptops. I’m thinking the parents of college students in particular would love being able to give their kid a place to study and write papers in the apartment/dorm but the luxury of taking that very computer with them to take notes.