The idea that most bathing throughout human history has been inherently communal is kind of absurd on its face.

It’s not like every single whole town or tribe would go to the same spot on the same river at the same time to bathe. Communal bathing may be common amongst some cultures and peoples but the mass communal bathing of the Roman, Victorian, and modernish ages was driven by necessity once you had too many people cramped into too little space, and there were also huge health implications from that lack of hygiene.

I also really do not trust the author napkin math about how much energy Roman baths used, nor does he even establish that household showering is a significant water or energy use compared to wasteful industry.