What replaced ferrite cores?

Ferrite cores in electronic applications have largely been replaced by materials like powdered iron and nanocrystalline cores, which offer improved magnetic properties, lower losses, and greater efficiency at high frequencies. Additionally, in some applications, air core inductors and other advanced materials such as amorphous steel have also gained popularity. These alternatives provide better performance in terms of power handling and size, especially in modern high-frequency and high-efficiency devices.