Not to mention the oxygen monitoring of nothingness.FT was one thing that was innovative and got killed for .3mm of nothingness.
There are some serious health issues that go unnoticed and for which it makes perfect sense to build monitoring into a common watch, e.g. blood pressure once this is doable. However, unless you have serious conditions which you most certainly know about, oxygen levels are just always at or above 95%.
People with chronic diseases should by all means benefit from advances in technology. But I don't see why 99% of the people can't get FT, more battery life, or a thinner watch instead of a useless gimmick.