I think you would be surprised. 1080p gaming is very much alive & 1080p gamers don’t need ultra high rez textures. I would certainly love to use this option. Sometimes people would even prioritize their data plan over graphics, because not everyone is so obsessed with graphics.
Especially if at download it was explained to users they won’t see a difference at 1080p, then even Steam & GoG could save some bandwidth. (plus it would be environmentally friendly)