I think the most optimistic outcome for Bitcoin would be to return to its roots, which is to play to the nature of bitcoin as a currency, as the opposite of global fiat currencies, coexisting with global fiat currencies and ready to replace the declining credit of fiat currencies, such as overissued US dollars.
Returning to its roots in terms of purpose is perhaps a good idea, but if terms of the levels of adoption, access to using it as currency and general publicity, it would be the death of Bitcoin.
I think that the most optimistic result would be if Bitcoin gets accepted as payment in supermarkets and cafés, and something is figured out about the fees, so people don't have to pay much for such things. And the number of users would get similar to that of the number of Internet users. But Bitcoin can also remain used for trading or as an investment. It doesn't have to be a choice, Bitcoin can successfully be many things.