> - What if Google that invented the core transformer architecture had kept the research paper to themselves instead of openly publishing it?

I'm pretty sure that someone else would have come around the corner with a similar idea some time later, because the fundamentals of these stuff were already discussed decases before "Attention is all you need" paper, the novel thing they did was combining existing knowhow into a new idea and making it public. A couple of ingredients of the base research for this is decades old (interestingly back then some European universities were leading the field)