The best capital improvements are the ones that you can obviate away through cheap behavioral or societal adjustments (just as the best line of code is the one you can remove or didn’t have to write).
[0]: https://www.theguardian.com/business/2021/mar/22/a-year-of-c...
(Not just flights - everything except essential goods including via trains, ships and lorries. Certainly all people should have been disallowed entry.)
Although I do believe there is a great future for public transit in coordination with lighter ‘last mile’ solutions simply because cars are way too bulky for cities.