Sigma delta DAC can shape the quantization noise. This quantization noise comes from the quantizer in the digital sigma delta modulator. But other types of DAC does not have this quantizer and no additional quantization noise is introduced. So sigma delta DAC is trying to shape the quantization noise which is introduced by itself only? Then what is the advantage of sigma delta DAC?
Sigma delta has other advantages - eg. use with Class-D output stage for good power efficiency, or "easy" to implement high linearity (with enough oversampling/noise shaping) in single-bit systems, as single comparator has no non-linearity (only gain error).
imagine the linearity of the elements(like resistors and capacitors) required if you want to implement, say a 24-bit dac. it would involve costly process with cap and resistor trimming and would be highly costly and impractical.