I personally don't think it's necessary and the downsides are you feel lousy (headache, irritability, etc.) when your levels drop. I have yet to hear of significantly better results on cycling. I had better results in terms of breast growth on oral vs injections and yet oral gives steadier levels of estrogen. Many women do quite well on patches and pellets although these deliver hormones in a very steady manner.
The cycling that goes on with ciswomen is unnatural insofar as nature intended women to become pregnant and breastfeed their infants most of their lives, spending only a small fraction of their lives cycling. Increased number of cycles have also been associated with an increased risk of breast cancer.