@Mister Cosmic You are spot on there, Adam does not wear himself out he is a lazy performer and does as little as he can.
Freddie on the other hand was a fire cracker and in the space of 5 minutes was sweating like a boiling kettle with all the running around to please the audience.
Mercury was a real live wire performer where Lambert is a fat lazy git.
Adam is saving his energy for the vocals, which are way more important than running all over the stage like a madman. I have been to three QAL concerts and he moves a lot more than you think. I believe he tries to highlight Brian and not be zooming all over taking the limelight instead of Brian. In his own tours he can zoom quite a bit. If you move too much it can affect the vocals, however I doubt that is the issue since he can sing perfectly from a prone position which is extremely hard to do. Each performer is different and Freddie was the star so everyone watched him. Adam wants Brian to get his due so he isn't nearly so busy otherwise people would be more apt to follow him and not watch the others. YMMV. But I don't think it can be called laziness. Singing for close to 2 1/2 hours is draining no matter how much one moves on stage and his voice is never diminished, the same from start to finish, so he may also be conserving energy to sing really well. I would rather hear great singing than someone who darts all over and the vocals suffer. There is a fine line there. I am not speaking specifically about Freddie, but have noticed this with other performers who are much too frantic on stage and they don't sound as good as they should.
Ha, Adam has very long legs and doesn't have to dart around to cover the same amount of space that Freddie covered. He just glides a couple of times and he is back to the middle of the stage. I admit he doesn’t climb all over the set like Freddie did but he does manage to maneuver the steps pretty well even with those 4 inch heels.