There's really no need to talk about "enough", "acceptable", etc.
It's very simple - if there's less money available for a first book, less people will do it. This means that there will almost certainly be less authors, therefore almost certainly less great authors (though it's probably not linear).
Not to say you're wrong, just that talking about "I think it's sufficient" masks the fact that it doesn't matter what you think, there will in effect be less great books written.
There's already very little money available for first books, relative to the many many people who give it a shot. I've worked at a number of publishers and trust me, the "slush pile" is always huge, always growing, and always hopeless. The other poster is correct that most writers will never finish, but more than enough still do.
It's very simple - if there's less money available for a first book, less people will do it. This means that there will almost certainly be less authors, therefore almost certainly less great authors (though it's probably not linear).
Not to say you're wrong, just that talking about "I think it's sufficient" masks the fact that it doesn't matter what you think, there will in effect be less great books written.