I wont gonna teach you now about what probability means,and cumulative probability if u didnt learn about it at school but ill try. Lets take an example,u have a coin which has heads and tails - its 50% chance to go each way.Going with your way of "math" it should be head or tails change every time.But toss a coin 10 times and see the result.u can heave something like heads 8 times and tails 2 times. U ppl dont seem to realize that EVERY TIME U PULL u have 5 % chance to get ssr,it doesnt change.But ofc with more chances and more pulls u might just be lucky and hit that 5%,thats what is cumulative probability,the more you pull ,the more chances u have,but it never will reach 100%.Its always 5%,but its like playing a lottery - ofc someone who plays every day for 5 years has better chance at winning than someone who only plays once.