Haha, many ways to eat an Oreo!
You can certainly look at it that way, it's like eating and "simply" eating an oreo vs. someone who is a professional taster and can break down an Oreo into 20 different teeny tiny bits. They can tell you exactly what composes the Oreo just by tasting it. Malcom Gladwell's fascinating book "Blink" describes in detail what these tasters do! Fascinating.
So you can eat the oreo and enjoy it, or you can be a professional, trained taster and taste the oreo and have your in-depth analysis of it. That's how Tarot is. One is not better than the other or more irrelevant than the other.
If your goal is to get the message across in a way yourself or the person you are reading for can easily understand and internalize to make changes in patterns of behavior or empowerment, enlightenment, whatever then study or knowledge of astrology, Kabbalah isn't necessary but it can be useful.
If your goal is to do research and explore the Tarot and delve into those layers (like the food tasters do) then yes, all of the other knowledge is useful and adds those layers.
Frustrating and in depth yes, it is. However it is so fascinating and so worth it. I have learned much delving into the Tarot depths of astrology and esoteric-ism but at the end of the day when my role as a reader is to empower and/or entertain people all of that other knowledge (which I do in some way bring to the table like any other experience I have) plays a role but it isn't the main thing or as important as meat, the message, of the reading itself.
As to the GD and other systems of thought pulling all of the occult knowledge out of thin air and corresponding it to the Tarot absolutely they did not. It is extremely relevant and it isn't an accident or coincidence astrology, kabbalah, esoteric symbolism and occult knowledge fits so well and in line with Tarot. They are all one and one leads to the other. "All roads lead to Rome" and all of these roads lead to the Divine.
One isn't better than the other, and the two need each other. It's like the mystics examining different parts of the elephant but only looking at that one part. In my opinion those who read Tarot intuitively "should" study the esoteric aspect of Tarot and those who study the esoteric side and are all about that "should" let go and read Tarot intuitively. There's the third, which is what exists between these two polarities.
For me the esoteric/occult knowledge was/is fascinating and worth the frustration to learn. In the esoteric study and meditation you raise the vibrations of the earth and connect with the cards on a deep level and integrate the cards into life itself.
That being said when I work at a party, restaurant, or fair I can't read the Thoth to save my life. It just doesn't happen, lol. These systems and knowledge, fascinating and relevant as they are don't (for me anyway) seem to translate in the fast paced party & fair world of reading the cards. In a long consultation the knowledge surfaces, but only to a small degree. If I put everything esoteric I know into a reading it would be information overload and the reading would render itself pretty much useless...in which case it would be an 8 of Swords moment...and then what good would it be? And yet the esoteric knowledge expands the understanding of the cards and their place in our world. A little piece or two esoteric information that I remember at that time might prove to be very significant/relevant to the person I am reading for, and that's just one more moment we have connected, or what I have said has resonated with them.
But both intuition and occult knowledge have their place and both breathe life into the cards. They are equally important and different ways of tasting the oreo, which is wonderful because then everyone and anyone can enjoy it. Tarot is universal, something for everyone.