I mean... if people don't mind reaching, so what? I purposefully don't remap my leader key, although I don't have many leader mappings so it's not like I'm reaching for it constantly.
I mean if people don't mind having cast iron glasses, sure
No but really, vim's paradim that you should go back to normal mode constantly. With the current situation you get posts on the vim subreddit asking/telling you about insert mode editing commands. You might as well use Emacs at that point, at least it would be the intended workflow
Possibly, though would have to see data, I guess. I feel like a lot of people are just curious about Vim and spend all their time in insert mode anyway. I have seen a bunch of those questions around "how would I do this without exiting insert mode" questions, though I'm not sure that having a more accessible escape key would change all of their minds. The "I want to use this new thing but I'm only interested in using it in a way that I'm used to" mindset is rampant among programmers.