An LDO has no switching noise, because it is a linear device. It also does not require an external filter for ripple rejection because it naturally has good PSRR (power supply ripple rejection). The graph on this slide shows the PSRR of the Toshiba TCR5AM11. It means if the LDO is exposed to a 1 kHz, 200 mVpp ripple, the VOUT will reflect this ripple with just 0.2 mVpp. This clean voltage output is critical for analog circuits that are sensitive to noise.