@Xaiyeon As counter-intuitive as it may sound, true RNG pulling gasha/scratch has been ditched in the gaming industry for ages, and it's gone for goods, because your pulling result very often will be far off from your expectation.
Games like G- Imp*ct, for example, use a set of very complex algorithm to control your pulls (You could call them faking the result). This algorithm normalizes the experience across the players, so players don't get "extremely" bad luck, also preventing players from getting "extremely" good luck (ex: getting 10 S ranks in one 10 pulls).
PSO2 NGS scratches as far as from my observation; they use a pulling table to ensure the pulls are close to the rate they are advertising. The algorithm first generates a big table with every item inside, alone with the appearance rate; whenever someone pulling the scratch, the table removes the pulled item from the table. Problem with this algorithm? So, say the hair has a 0.34% chance of appearing, in theory, if a person is pulling the entire table, he should be expecting to get 34 hairs every 10000 pulls. But in reality, since there are many players pulling the table, you may end up not getting a single hair in 10000 pulls because all the hairs are pulled by other individuals. Sega might have aware of this problem, and their solution is to provide you with those pity choice tickets, which generate you a hair outside of the table.