The Whoop is like 90% accurate compared to it: https://www.youtube.com/watch?v=9SzUDTBK-i0

It's just trade-offs: if you're using the Whoop, you don't want a screen and you like two weeks battery life.

Wearables are a tool for motivation. All I need is for it to hold me accountable and get me to exercise a little more than the day before. Whether I actually burned 900 or 950 calories is inconsequential.

(Of course, when it comes to the FDA-regulated health features that's a different story. Those absolutely do need to be accurate.)

So many people fall in this category, but a lot of them seem to min-max their gear more than anything. I know casual runners with $400 carbon plate performance shoes, I run with them, in my $7 decathlon shoes, unless you're paid to run or aim for a record I really don't see the point, especially since these thing barely last a few month of serious running. Same for hikers with $3k of ultralight gear, they spend more time reading reviews and flexing their 0.1g hacks than actually hiking.

There is a huge overlap between tech nerds and "gear hobbyists", I assume because they have too much money for their own good.