CSS floats, once key to web layouts, are now obsolete due to fragile behavior (float hierarchies, weak vertical alignment, margin/padding quirks, no semantics) and poor fit for responsive design; the article urges switching to Flexbox and CSS Grid, shows migrating a float‑based e‑commerce site to a responsive grid, and highlights real‑world uses and a forward‑looking shift toward more maintainable, flexible layouts.