I would think the answer depends on the gig.
The music is still hopefully evolving, and who can say where it will go. As the PA's become more sophisticated, yes, I suppose that the bass can be specifically accommodated for some situations with no amp. As players, we should be open to this as a possibility and figuring out where to take it.
However, for a straight up blues gig, roots rock, or classic R&B, it will always be the self standing amp behind the player; because that is a part of the form, plain and simple. Not that you can't play, for example, blues with a sophisticated PA setup and no amp; just that isn't part of the form. And, if it ain't broke don't fix it.
The music is still hopefully evolving, and who can say where it will go. As the PA's become more sophisticated, yes, I suppose that the bass can be specifically accommodated for some situations with no amp. As players, we should be open to this as a possibility and figuring out where to take it.
However, for a straight up blues gig, roots rock, or classic R&B, it will always be the self standing amp behind the player; because that is a part of the form, plain and simple. Not that you can't play, for example, blues with a sophisticated PA setup and no amp; just that isn't part of the form. And, if it ain't broke don't fix it.

IMO.