One thing which I am struggling with is that when you have a scenario when from (say) 10 teams you have 7 different initiatives going on, each initiative enhancing the same product to appeal to different usages in the vast market. How do you identify a constraint in this scenario? Would it be practical to suggest that all 10 teams should be working around one initiative?
No, teams should work on what is needed.
If work streams are truly independent then you would have distinct constraints as well. But it is extremely rare that what appear to be independent streams are really such. That’s why it is beneficial to reason in terms of virtual constraints - and they are much easier to find, because often they come out of deadlines (e.g. Year’s End closing of books).