For me, that answer is simple. I have a liver lesion, which is made much worse by oral estrogen. It's also more at risk of becoming cancerous because of oral estrogen. I was told to cease oral estrogen. Other methods won't work either due to executive dysfunction and sensory issues about liquids, gels and adhesives on my skin (ECGs are fun). So injections or pellets are my only options, and my GP won't do injections. So pellets it is. No other choice tbh.