250.118 is about conductors suitable for grounding equipment - not the equipment [I consider grounding electrodes to be special equipment being purposed to a system, not simple conductors, but who knows what the code guys would say if you put it to them that way]. 250.52 does permit using water pipes, but does not demand it.
What is demanded? Any one of the 8 methods listed. This is different than bonding requirements on certain plumbing, which is supplemental to the main protection provided for fault currents - bonding is not about the system, but specific equipment.
The business of using water piping makes it totally confusing, like trying to define front/back/top/bottom of a sphere. Why bother? A system will always have grounding installed, but bonding comes and goes depending on installed equipment.
Am I going to bond when an electric water heater is installed? Heck yeah. It's hairsplitting [I know], and like a lot of things in the NEC, the pictures and drawings the guys were looking at when they wrote text are missing, and their vetting of language is weak. I doubt any verbiage gets tested beyond voting for adoption of proposed changes.
There's a lot of situations where you can look at a physical setup or drawing and then see that code makes sense, but if you start knowing only their language and try to imagine the setup, you find they need help - lots of it.