It sounds like your primary criteria for the success of Bitcoin is that significantly more people use it than currently do. Is that correct? Would you consider Bitcoin successful if, say, it kept the same number of users as now (give or take a factor of two)?
My primary criteria for the success of Bitcoin is not just that significantly more people use it then currently do, however I do believe that this is an important criterion, but quite pointless by itself if Bitcoin became like Visa for instance. So increasing adoption while maximizing decentralization and financial freedom would be a more accurate criterion for me.