Recumbents by virtue of their geometry are a little heavier than a similarly equipped road bike.

When you include the fact that it's impossible to unweight the wheels, you need to either run a wider tire (negating a portion of the aero advantage) or have a suspension to help soak up the bumps to achieve a comfortable ride on less than ideal road conditions. This moves them from a 'little' heavier to a 'lot' heavier.

Carrying 5 extra pounds of bike isn't too big a deal in terms of climbing speed, but 20 extra pounds becomes pretty significant.

As stated above, you can only sit and spin in one position on the bent. No ability to get your upper body into it, or move around on the bike to recruit different muscle groups.

Are they 'better'? Depends on what you want. For a flat land, smooth TT, yeah. Check out HPV races. For touring? If your butt or neck just can't take riding on a road style touring bike, then yeah, a recumbent would be 'better'.

Different horses for courses.