All the weapons were the same in FFX, too except that you could add abilities to them. The difference is that you use accessories with the abilities because with the class changing, you'd otherwise have too many pieces of equipment to manage. Remember that by the end of FFX, you have an airship dedicated to carting you arround. Wouldn't it kind of not make sense if all the sudden you have to walk everywhere again? The point of doing the missions is to get information about what's going on and/or to affect it. While FFX-2 was certainly different in many respects, I don't think it was a bad game. A lot of questions were left unanswered at the end of FFX, and if you never really cared about it in FFX, I suppose I can see how the parts of FFX-2 dedicated to answering them wouldn't interest you.