When I applied for this visa in 2016, I asked the same question directly at Tech Nation.
And even then, on such an early stage of this visa route existence, the reply was pretty similar to the answer, that you got from @Mukesh_Adhvaryu.
The situation is clear, and logic is straightforward.
When we think about companies, for example, GAFA or The Big Four, it is not a good idea when even a high-level manager uses the corporate brand to promote someone who is not working in the company with thousands of employees.
Additionally, I think for you, it will be useful to read these articles on my Blog:
- CV of the referee in Letter of Recommendation
General Questions on Endorsement Stage (here I also asked a similar question, it is no.5 in the list)
- Basics of Recommendation Letter
I hope these thoughts were useful for you and if you still have unclear moments - let me know, I can share my experience with you.