This kind of sucks. Most of my points transfers from Amex are to Emirates for flights and upgrades. Sometimes it’s better to book through the Amex travel website or concierge though.
In any case I love being in Asia as it makes sense to always use EK when traveling to Europe. Emirates business and first class is the only way to fly commercial.
https://thepointsguy.com/news/amex-membership-rewards-devalues-emirates-skywards-transfers/