Bass amps are not simply about convenience and/or practicality (or the lack thereof) for many of us.
I simply enjoy hearing myself through speakers. When I can, I will bring an amp. If I can get away with it, I'll bring an Ampeg SVT. The sound of that heavy beast makes me smile.
They absolutely will be less common in a decade or so. We'll probably all have wireless basses with transmitters you can't see that send a signal directly to the computer used to run sound (that is the size of a pack of gum). Every audience member will be wearing headphones (tiny earbuds) that allow them to control the volume of their live band. Take out your earbuds and all you will hear are people talking and the sound of sticks hitting electronic drums pads. Your average bar will sound like a library until you put in earbuds.
So, not yet... but it's coming.