Interesting questions, Which I di not think anyone can yet answer Let's wait a bit more to see if it is a pattern or just a anomaly. .
On infrastructure , I can.t talk about the airline industry in the US, not my area of expertise , but on ATC I can give you my opinion : it is antiquated , roughly still using 1980-90 technology , was never properly modernized , and it still massively lacks staff , certified ,controllers that is .
, Solutions? , on systems : one would be to privatize the Service provision (ATM) , it was attempted a couple of years ago but the AOPA lobby killed the idea. Modernize to 2025 technology ? , means a huge budget, and building new Ops rooms in each of the large facilities, , train people on it while in parallel running the old system . For this you need lots of extra staff , which they do not have , Doing this without extra staff would mean drastic restrictions on traffic during years, not weeks. Can't se that happen either.
Only way out , first massively recruit and train large number of controllers, while building the new infrastructure .with modern technology . in 10-12 years you might get there , if you are lucky.