Why did classical physics predict that Rutherford’s orbiting electrons would be unstable?

According to classical mechanics and electromagnetic theory, the Rutherford model of the atom was considered unstable because any charged particle moving along a curved path must emit electromagnetic radiation.12

Because the orbiting electrons would continuously lose energy through this radiation, classical physics predicted that they would inevitably spiral inward and collapse into the nucleus. To resolve this, Niels Bohr proposed that electrons exist only in specific, quantized orbits of fixed size and energy, where they do not radiate energy unless they "jump" between these allowed levels.123