The point of martingale is if you can find an area where if you have slightly better probability of winning the next roll or losing.
For example, you had 30 losses in a row at 50/50 odds, what are the chances that the next 30 rolls will be mostly winners?
What do you mean by that? The bets are independent of each other, and your win chance of the next roll is always the same, regardless of your previous rolls. After having 30 losses in row at 50% bets, you still have 50% chance to lose the next one.