They gonna have to move the capital to Highgarden because they cant fix all that shyt in her lifetime. Not to mention she killed the workforce.
This is almost an aside, but King's Landing has always been in need of being rebuilt. It started off as a little fort on a hill for Aegon. People started building little hovels and hastily built gates and walls around it and it quickly became a city with thousands and thousands of people without the infrastructure or planning to handle the sudden growth. Because the central city planning involved with the construction of the city (or the lack thereof) was so poor, the city eventually became the ugly, inefficient city that it is now, with crooked cobbled streets that are too narrow, wooden shacks built on top of each other, and a huge sanitation problem. It's the youngest major city but has the worst sewage, so bad that Olenna always comments that you can smell shyt from miles away
The pipes carry shyt from the Red Keep to the river, but the pipes overflow during rains and the shyt literally floods flea bottom
Cities like Old Town and the cities in Essos put King's Landing to shame in terms of architecture, wide paved roads/streets, sanitation, sewage systems, clean drinking water, market squares, and overall management of their population, etc which is pretty bad for the capital of the seven kingdoms
King Jaehaerys took out loans from the Iron Bank to pay for improvements to the city, but the most time and coin was put into constructing the dragon pit, monuments, Red Keep, and the King's Road. It was kind of too late to fix the city at large aside from widening some streets, without totally destroying it and starting over.........
Well......
With the city now in ruin whoever sits the iron throne now can essentially rebuild the city from scratch and this time plan it so that isn't a mindlessly thrown together piece of shyt