[4gotunameagain]

People are downvoting you because it is simply due to the different materials and building methodologies of the past.

Things took much longer to build and were much more expensive, but they were very durable as an effect.

There were no plastic hot tubs in Pompeii that burned when the pyroclastic flow swept past.

[shawabawa3]

There were no plastic ones but there were very probably some wooden ones, or other luxurious wooden items which were destroyed without a trace and we'd never know

[perihelions]

I mean, they certainly knew how to make wooden water containers: they wrote it down. This context is dye-making rather than baths,

- "...This water is boiled with an equal quantity of pure water, and is then poured into large wooden reservoirs [original: "piscinas ligneas"]. Across these reservoirs there are a number of immovable beams, to which cords are fastened, and then sunk into the water beneath by means of stones; upon which, a slimy..."

https://www.gutenberg.org/cache/epub/62704/pg62704-images.ht... ("Chalcanthum, or shoemakers’ black: sixteen remedies" (77))

https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext...

[therealpygon]

“People” often fancy themselves to be smarter than they are and capable of judging others wrong based on their limited information and passing knowledge, as well as what they have decided to be true rather than what is fact. Things like “because things were made of stone, all things were made of stone”, or “because some things survived the tests of time, all things were built better”.

It is exactly the bias that was pointed out by the commentor.

[4gotunameagain]

I highly, highly doubt that the ratio of durable to perishable baths, spas and jacuzzis is now higher or even similar to what it was back then. Will we ever know for sure ? No, of course not.