Sorry, I did not realize. OK, water treatment plants are off limits. They should not be targeted.You're forgetting about water treatment plants, which were also included in your list, and are clearly listed as part of the critical infrastructure prohibited as a war crime.
And what you were actually advocating was the total destruction of the economy (which by the way, I already told you is stupid thing to focus on in a modern conflict because you can just directly destroy the military and it will have no chance to regenerate for decades). Destroying a country's economy will kill millions of civilians due to poverty and it serves no direct military purpose in the 21st century, other than American-style oppression.
There's also no reason for millions to die to poverty. As for destruction of certain sectors of the economy, it is a military necessity (especially bridges, which you see here that Ukrainians are doing to themselves even). For civilian survival, food and water aid is typically provided (see Iraq 2003, Afghanistan, Yugoslavia).