Also, you get the more complicated systems. I see this happening right now.
Once upon a time, we had a large, complicated system, and even though it transported both water and electricity, and different customers consumed them, we still tried to move them through the same pipeline. Eventually, the system managers got smart and set up unique delivery systems for both products.
All were happy. The customers got their water; others got their electricity; and those who needed it got both. There was another subsystem that delivered natural gas, and demand was seasonal, but they decided to just put them with the water people. It worked, but the seasonal nature of gas vs water created some problems.
Then, suddenly, the managers thought things would go better if they tried to transport water, gas, and electricity using the same pipeline again.
Things are messy.