Conditioning is sorely lacking. Elite level (Olypic cliber or world-class) athletes have 15-20% body fat (80-80% lean muscle mass). They look "different", more vascular. (Even Serena is getting "smooth" - look at pictures from her 1st US OPEN over Hingis in 1999 - you could see the cuts and muscles in her arms and back.)
Alex needs to do some SERIOUS core work. She is carrying 10-15 pounds of worthless girth. Additionally, the shoulder/wrist injusries have much to do with "too much arm" and not enough torso rotation.
Technically, she has some serious weight-transfer issues with her serve. She is almost off-balance (falliing forward - too much weight on her front foot/knee/thigh) when she should be propelling herself up into the ball. Her toss is often on the left side of her face, instead of over her nose or right eye (flat/topspin or slice, respectively.)
Alex rallies TOO much (right up the middle) instead of setting up closing shots with forcing groundstrokes (toward the sidelines, which open up the court). She stands too far behind the baseline (on ANY surface). The reason she "showed up" at Wimbledon is that the grass surface places a PREMIUM on the most important stroke in the game (THE SERVE) and less on "rally tennis" (forehands and backhands). While she looks good hitting a backhand, it is NOT a finishing stroke, barely a forcing stroke.
That is why she is no longer in the top 100. She IS NOT WILLING TO DO THE WORK, but is content to ride the wave (quickly dissipating) from her intial spalch at Wimbledon so many years ago. UNREALIZED POTENTIAL? Well, she did better than Anna Kournikova, who also made a semi at Wimbledon, but NEVER won any WTA events. But NO ONE is afraid to play Alex, she is too busy looking like a tennis player and handling off-court distractions, and has removed herself from the HARD WORK that a PROFESSIONAL ATHLETE must make as a daily creed.