Did the clothes in 1900 last longer than they do today? Did they even have polyester?

Clothes lasted longer, yes. The fabric was almost always thicker and less finely woven due to the limitations of historical textile manufacturing. The garments themselves were properly stitched instead of overlocked, with patterns sensibly designed for the usage and size of the garments. People also repaired their clothes and would keep them long past the point most modern consumers would buy new.

Plus, clothes were a considerable portion of the household budget. People couldn't afford them if they didn't last.