To be fair to the Zoe study it has 4.6 million people recording their wellness ref covid every day - my wife and I amongst them. you report whether or not you have had a covid test since the last time you reported (I haven't), whether you have had a vaccine - they want to know when and which batch, have you had a follow up vaccine, same data and, eventually (this literally takes 30 seconds each day) if you are feeling well or unwell. In the six months or so I've been doing this I've had two off days when I really didn't feel too good and pushed the unwell button - they ask you to identify from a longish list of symptoms which ones apply to you. I didn't develop CV so my data probably didn't help them but by catching it before the event is probably the best data they can get.
All of this data means that they actually have a better chance of knowing which symptoms are more likely to indicate covid coming on - it's the largest such study in the world - so, yes, they might have an eye on the research funding gravy train but I suspect that they're earning it right now. With way too many people of my age group in my personal circle succumbing and dying of CV right now I'm supportive of them and would encourage all biscuiteers to download their app and participate.
