I wouldn't call it "only". Bringing my feelings, thoughts, fears, doubts, hopes etc to the surface, allowing me to focus on them, sort them, clean them etc is a great thing. I believe that we know many things without knowing that we know them.
Let's compare it to a drawer. Lots of things are stuffed in this old drawer, I HAVE these things, but I have no control over them, I don't even know what's in there. Taking this drawer, cleaning it out, putting things into place or fixing them, and putting everything in order with clear knowledge of what I have and what I don't have - that's what I do in a tarot reading.
I don't believe that tarot cards can tell me something outside of myself. But I believe that I have via tarot access to my inner wisdom that can help me get a grip on my life. Clearing out these old drawers that we store our old emotions, traumata, dreams, vision and beliefs in...
And that's why for me, self-readings work.
I also like using the cards not only for readings but for strengthening my resolve, affirmations, meditations etc., inspired by Nina Lee Braden's excellent approach. Picking the three cards whose energies I will need in different stages of a difficult project before me - for me, that's a great way to get control over my life, focusing my energies.
I did many of Braden's exercises. Which tarot cards characterize my mother, which our relationship, and which card would advize me best how to strengthen our relationship?
Just thinking about these questions and picking the cards gives me access of layers of wisdom and knowledge expressed in wordless symbols, like dreams.
No, I can't call my feelings and thoughts "only", it sounds a bit belittling to me. Ymmv of course.