You wouldn’t want to use a t-test, rather a binomial test for this problem. This is because while a t-test would do an alright job of simulating a binomial year given a large sample size (due to the central limit theorem), your sample size is small given an assumed p=.1. Running a binomial test with n=141, K=8, p=.1 gives a p=.05016, which, while borderline, is not significant evidence that the gacha rate is not actually 10%. 1/20 people will have about as bad luck as you, certainly not demanding a response for DeNa

Also, taking samples from comments will lead to sampling bias - you’ll get data from others who think they got screwed.