The sacred rituals speed up advancement. I spent years purifying my soul and chakras, following instructions from the Gods which isn't always easy unless you are psychic enough, which I barely was for a while.
But now with Advanced Purification ritual, members can purify themselves in much less time. High Priest told me I don't need that ritual because he could tell I was purified enough. On a Witches Sabbat I would begin a purification cycle, but on the 2nd day there would be nothing to purify. So I don't even have that ritual, but members can buy it and save themselves all the time I spent in the past.
So no, you don't need that ritual to purify yourself.... but it will save you years.
The sacred rituals will save you a lot of time, and a lot of trial and error. You get the instructions right there, written so you aren't second guessing what you think your GD may or may not have told you, or wondering if you're potentially foolish for doing what you were given in a dream.
And as for money, it's been said again and again. If you can't afford the rituals, do the free money workings in the ToZ. Lakshmi, planetary squares, runes, these all work. You will then get the money to buy rituals, especially if your GD is backing you and knows your intent to support the ToZ and buy rituals. Do the free money workings to get enough money to buy the first wealth ritual for the lowest price, then use that ritual to get more money for more rituals. That is what some members have successfully done.
The sacred rituals will make you far more Divine than not having them, so the Gods will help guide you, but you need to remain open to new opportunities or different ways of making money, not just being stuck on one mindset or one goal when it isn't even right for you.
And for other sacred rituals, they give what only they can give. Sure you can advance without them, but you will advance in more ways with them. Doing what is free in the ToZ and in posts here will advance you, absolutely. But you will benefit from the sacred rituals even more.