First off, I haven't worked régularly in the US for 30 years so my local taxes are not what you thought.
Secondly, my muslim collegues go without food & water all day for a month every year so in real terms neither is neccesary in 99% of all jobs.
Lastly, while i do not contest that employers in the US must be constrained to make toilets available, to my knowledge, there is no constraint on this being free, so I see no substantive difference between a free lunch & unmetered acces to water for sanitary purposes.
Our major difference of opinion seems to be that you think that free lunches are an exception that it is normal to eliminate as hidden benefits according to current tax laws in the US, whereas I see it as the sign of future micromanagement by pin headed tax assessors that should be fought against.