The guy is the GOAT and while he was alive… many… many… other artists also saw him that way. His contemporaries absolutely adored him, and even tried to emulate him. His work was known to be important during his life to even the most financially successful of painters.
I suppose if you limit the concept of “success” to how much money one earns in their life, then fine Van Gogh was not very financially successful, but he was monumentally successful and recognized as such during his life by the only real measure that matters: Impact.
This is why as a journalist or a writer, it is important to confirm “what you know” before committing it to a piece. If you don’t verify everything you risk perpetuating myths instead of realities.