I consider down a great one-night stand but a poor long-term relationship. Down is best for weight/warmth when you’re only planning on one night out.
Hydrophobic Down has not panned out despite (I can personally attest to this as I had a front-row seat) millions of dollars spent investigating how to do it well. The ‘coatings’ on the down either wash or wear off very quickly usually leaving the down feathers worse off than they would have been without treatment (specifically they clump up). That, for now, is a dead horse.
Synthetic is still the way to go and getting better each year.
One caveat, do not buy a synthetic belay parka with a goretex shell, that totally mis-understands how a belay parka works to move moisture out of your clothing system.
RE the future, I’m currently in possession of a next-gen synthetic belay parka that is super warm and, as a full-size-all-conditions belay parka weighs about the same as a similarly insulated down parka. I’ve been testing this jacket for 2 weeks (full-disclosure: My day-job is Patagonia Ambassador)
I’ve worn synthetic parkas (mostly the DAS Parka) and pants (DAS and MicroPuff) on numerous 8,000 meter peaks climbs and summits as well as hundreds of days in Alaska and elsewhere. These jackets have literally saved my life many times.
What’s more, I consider a synthetic belay parka to be my winter-conditions outerwear. I don’t use goretex or similiar waterproof/breathable shells ever unless I know i’ll be in rain (ie. Scotland in winter). I still use a Houdini Jacket as my primary shell for almost all winter climbing and skiing. If i need more, I throw on a Hyper Puff Belay Parka which is basically all (winter) weather protection.
Hope that helps, I’m sure others will have opinions on this as well that will also be valid.