I completely agree with you.

The people in power don't care, and they don't intend to spend more money on main replacement. And they'd rather spend a few million here and there, so they can put off spending a couple billion until they are no longer in office. At the end of the day, recycling wastewater would be cheaper than replacing the mains, especially when you add in the fact that many cities have to buy their raw water from an outside entity. In Texas, we buy raw water from water districts. There are cities here that built reservoirs before the water districts ever existed, but now they have to pay for raw water coming out of their own lakes. Recycling wastewater means you pay for it once, and use it over and over. If I discharge it into a river and then pick it up again downstream, I get to pay for it all over again.

Another thing to add perspective to the main replacement thing: Chicago alone has over 400,000 lead service lines. These lines are an active, major health risk and they are only removing dozens of them per year, when they should be doing thousands. If death and lawsuits aren't bringing replacements, they definitely aren't going to go replacing mains over some water loss.

Lastly, forcibly reducing irrigation is the lowest hanging fruit, as we can see on the west coast right now. Irrigation use is much more than 10% of the treated water in the south. Eventually, I'm hoping we will get on board with mass-scale desalination, hopefully powered by nuclear power.

It's frustrating to say the least. At the pace we're going, we will have all the cast iron replaced in 50 years. By then, the ductile will be 90-110 years old, and the PVC will be 50-90. The math doesn't add up.

The obvious answer would be that treating wastewater more is cheaper than replacing hundreds, if not thousands of miles of mains. Treating wastewater more is also forever, while you're going to have to replace all the mains again in 50-75 years if you want to prevent water loss from skyrocketing again.

The city I work for is doing proactive leak detection (the program I run), DMAs, transient monitoring, meter calibration, etc. to lower water loss. We've been doing some of these programs for years now, and we were one of the first in the state to do proactive leak surveying. We still have high water loss. We're talking thousands and thousands of leaks over the course of a year. Our system is old, and we don't have the money to replace it all at once, nor the physical resources.

As I said, I run the proactive survey program, so I'm a big proponent of reducing water loss. That being said, cutting 1-2% of water loss is difficult to do, and very costly. Any city that needs to drastically reduce consumption in the next decade will only be looking at water loss as a longer term plan.

UCLA said that the LA area reports of 3-7% water loss are because main breaks are being counted as "Unbilled, Unmetered consumption" instead of loss in some areas, and state of the art utilities still report a 10% water loss. I also found a Reuter's article stating that over 25% of the water mains in LA are teetering on 100 years old. I think it's safe to say that their figures are incomplete at best.

The relatively large Texas city I work for ranges between 10 and 20% depending on the year.

https://www.ioes.ucla.edu/news/california-water-agencies-dont-know-much-pipes-leak-ucla-report-finds/