chess.com does have a take back option.
Random rant... aimed at nobody in particular

I totally understand and I can relate to that because I've lost many games because of mouse slips and I couldn't do anything about it .
I totally understand and I can relate to that because I've lost many games because of mouse slips and I couldn't do anything about it .
I apologize for the rant, but I just have to let steam off a bit.
I think I'm done playing rated games. I just started one against someone rated over 100 higher than me, and I was ahead, when I did a mouse slip moving a rook (trying to capture my opponent's rook), failed to move it far enough, and just gifted it for no compensation whatsoever. Immediate resignation. No need to keep playing.
chess.com has no takebacks, so if you mouse-slip, it's over and there's nothing you can do about it. (Although, I suppose in a way it might also be a blessing in disguise. It might be even more frustrating to ask my opponent for a takeback because of an extremely obvious mouse slip, but my opponent opportunistically taking advantage of the situation and grabbing the win. When there are no takebacks, there isn't any such opportunism either.)
So yeah. I think I'm done with rated games. With unrated games it doesn't really matter all that much.
On another tangent, I think i'm also done with time controls shorter than 10 minutes. The major problem with them is that they often cut very interesting games and positions short. Many, many, many times I have been in a complex situation that would have been very interesting to think about... but the clock just runs out and I lose on time (or, perhaps even worse, it forces me to move without having the time to think). Such time controls just don't make any sense. They just ruin interesting games. So not for me, sorry.
As of right now, I think I'm going to take a break from chess completely. I just hate those mouse slips. They rather obviously don't happen in real-life games. I'm sick of them.