Waitbutwhy has some interesting posts about what they see as the role of each company. The Neural link one summarises them at one point (though is an enormous article, and a great one).

https://waitbutwhy.com/2017/04/neuralink.html

As an aside, they have some really wonderful long form content. I love the 1 to Graham's number posts (a two parter) https://waitbutwhy.com/2014/11/from-1-to-1000000.html