Especially at the beginning, I think reading is useful. It gives you useful pointers and makes you cognizant of various obstacles and traps you’re likely to fall into. I think excellent literature offers a compass or can be used as scaffolding.
If you want, you can simply throw yourself into contemplation instead. But some theory makes you consider different perspectives, even if perspective is irrelevant relative to enlightenment.
Although it is ultimately not needed because in order to grasp You, you only need You. Consider the example of Ramana Maharshi. He didn’t even hold the notion of enlightenment and yet he got deeply and permanently conscious in an instant.
In terms of life success, absolutely; reading is a must in my mind. Naval Ramikant, for example, is an entrepreneur that endorses reading as essential for his success.
Even without practice, a book in the right time can change your perspective or disposition, or inspire you. This can make a difference. But hey, I’ll tell you when I get successful (rich). 😄