The capability for such a list to exist is entirely possible. I'm not aware of such a comprehensive list existing - for it too list the millions on a single web page is huge and not very useful for the sake of research.

But - the roll of honour does exist online for the British forces. If I may dip into a more personal recommendation at the slight exception to the subreddit rules, please excuse me. For the 1st Australian Imperial Force which served in the Great War, I have in the past done several research/location trips to find relatives along the Western Front/North Africa. As I mentioned earlier, there is a searchable roll of honour for Australian forces at the Australian War Memorial site, as well as a Red Cross roll for those injured/killed and a Commonwealth War Graves Commission site for searching through the many cemetaries dotted across northern France.

This long list you're hoping for is more of a database format rather then a long, singular list.

If you happen to know of anyone who served in the war - be it vaguely or personally - I would recommend having a look. It is both touching and tragic. Here is the AWM roll of honour. / Here is the Red Cross roll. / Here is the CWGC site. / Here is the roll of honour UK (paid) /

As a quick side note; I would like to comment that while Australia has a government-sponsored free site which allows you to view every war time document; unit records, original scans of the enlistment papers of every Australian soldiers, death notices, etc etc, the United Kingdom appears to be a lacking such a central database beyond a list of those killed (behind a paywall!), which is a shame.