Atlasing textures in rectangle

Hi, was just wondering if tiling textures on top of each other is bad practice. Although I heard rectangular textures can prevent compression on some mobile and older devices, is it—aiming generally for desktop—a bad idea to start stacking textures? Thinking perhaps like a 4:1 ratio (or more?). The reason is that the textures need to wrap around in one direction and I want to save in on materials. Thanks!