Why are quests setup in a way that you are forced to use a Google Account?

I would have loved to finish my recent quest: "Agentic Workflow Automation Quest". 

But in the last step we are asked to hand in a short video by - you guessed it - by google or by the use of google forms, to be more precise. 

Well, now there are still a few that refuse connecting with google for data security reasons. And as much as I would have loved to contribute ... I will never sign up with google ... and above all provide them with my telephone number. No no no ...  

So my point is: Why is that done in that way? There are way better ways to have people handing in their videos/contributions. Why willingly exclude certain potential participants? 

Just my 5ct ...