Hey,
I'm also taking Sociology and Psychology. I use quizlet and also started using gizmo. I can't really speak to too much for Anki but what I did find that a lot of STEM students tend to use it rather than humanities students (but I do know that there are law students that use it too) and it also is solely for flashcards, they also spaced repetition features which is quite useful.
I really like quizlet as it's quite easy to get the hang of and there are also hundreds and thousands of flashcards for all three of those subjects which cover all the exam boards as well. However, the problem that I have with it is that the features tend to be really limited if you don't have quizlet plus, but getting quizlet plus is worth it (in my opinion anyway...), they also have features asides from flashcards such as ai which you can use to help learn more in-depth about certain topics or consolidate your knowledge or they mini-games such as matching the term to the definition.
Gizmo I have only started using recently, which has similar features to quizlet with flashcard features, however they have more unique features that aren't hidden behind a paywall like they teach you topic step by step from a flashcard deck, which I found very helpful. There are also thousands of flashcards for all the subjects which are sorted by exam board and even by schools.
Overall, I'd recommend both but if you are looking for something that's just for flashcards I'd probably use either anki or quizlet but if you are looking for other features like quizzes and ways to "gamify" your learning to make it more fun then probably look into quizlet (plus) or gizmo. I hope this helped ❤️