I haven't read your other thread about Stake being... a family run scam business, and as I am not a tech geekie, I have to resort to a quick search at the internet about motion sensor, some explains that it's implemented on tablets and phones to help determine the screen orientation through gyrometer etc., help enhancing gaming experience by translating touches and gestures into action [temple run, anyone?], fitness app tracking, but one that explains quite nicely about brave in desktop, that blocking motion sensor from a website that doesn't need a motion sensor by logical reason [pizza hut for that case, stake for this case] is this snippet, that hopefully could help provide readers some insight:
[...]
As it turns out, one person has dug down to the very bottom of this mystery; that person is Grant Winny, a developer from Ohio. Grant followed the code trail after noticing the motion sensor alert on several sites, including the same site we visited, Pizza Hut:
It turns out that this is a function that Akamai is behind. Akamai is a massive online content and content delivery system. Grant Winny concluded that this is a script developed by Akamai to determine whether a visitor to a website (i.e. the visitor’s web browser) is a bot, saying that it is “using sensor data like accelerometer capabilities to determine whether a requestor is a bot or not.” (You can read his very in-depth analysis of the whats, wheres, and whys here.) [...]
I didn't read to the bottom of the page, but I think we have our answer why stake asked for it: to detect if you're bot or human.