There are a lot in theory but in practice most of the ones in this picture aren't used, especially not all by one person.

Each person generally can have up to 2/3 pronouns they use. One for acquaintances (and the one you use most of the time), one for strangers where you need to be a bit more formal and then possibly one for when you're speaking to someone in a higher position. Outside of that, only very specific scenarios would require a different pronoun.

Andd for example if you use "watashi" with acquaintances, that one's also valid in many formal scenarios so you wouldn't need a separate one for that, you'd only need a more formal one like "watakushi" when speaking to someone in a high position. So all in all it's really not that complicated.