Baths are mostly a holdover from the time before modern plumbing when a shower was just plain not an option. Heated water pumped through pipes at pressure! What black magic is this???? A bath OTOH required nothing more than a large tub and a stove to heat water on. The weekly family bath was a thing and everyone used the same water. Is there any wonder why perfumes and fragrances were so popular with the upper classes? Though it has been shown that even the peasants toiling away in fields and living hand-to-mouth took better care of their hygiene than it is generally assumed. Bath tubs are still commonly included when building a house because they still do offer some utility. But even if no one ever takes a bath the tub itself serves as an excellent base for a shower, and it is not that much larger than what just a shower stall would take up. And bath tubs are great when you have young children or to wash the dog or just for the occasional soak. Showers are a better solution from almost all perspectives but that doesn't mean that having a bath tub around for when you need or want it is a terrible idea.