It has been a very influential book.
See the so-called linguistic turn in analytic philosophy.
The book is obscure and fascinating.
Part of its success can be due to its obscurity, leaving place for so mavy interpretations.
The book itself claims to be "groundbraking"; see the Preface :
The book deals with the problems of philosophy, and shows, I believe, that the reason why these problems are posed is that the logic of our language is misunderstood. The whole sense of the book might be summed up in the following words: what can be said at all can be said clearly, and what we cannot talk about we must pass over in silence. [...] I therefore believe myself to have found, on all essential points, the final solution of the problems. And if I am not mistaken in this belief, then the second thing in which the value of this work consists is that it shows how little is achieved when these problems are solved.
See : Ben Ware, Dialectic of the Ladder : Wittgenstein, the Tractatus, and Modernism, Bloomsbury (2015), Preface :
Wittgenstein’s Tractatus Logico-Philosophicus has fascinated and perplexed
readers since its publication in 1922. It is a short but intense work, made
up of a series of highly compressed remarks or ‘propositions’. These
remarks, governed by a strict decimal numbering system which
Wittgenstein considered vital to securing the book’s overall clarity, deal
with a range of topics: the relation between language and reality, the nature
of logic, solipsism and subjectivity, the role of ethics and its connection
with aesthetics, mysticism, and the aim of philosophy. Whilst there is
nothing philosophically obscure about these themes, the book itself is
notoriously difficult for readers to understand. Wittgenstein himself
anticipated this difficulty in a letter to Bertrand Russell in March 1919:
I’ve written a book called “Logisch-Philosophische Abhandlung”
containing all my work of the last six years. I believe I’ve solved our
problems finally. This may sound arrogant but I can’t help believing
it [...] [O]f course [...] nobody will understand it; although I
believe, it’s all as clear as crystal.
[...] two features which make the Tractatus particularly challenging for readers. The first is the style in which the book is written. [...] The second difficulty for the reader concerns an apparent dissonance within the Tractatus itself. Despite appearing to put forward logical, linguistic and meta-philosophical theories in the body of the text, Wittgenstein writes, in the book’s penultimate section:
My propositions are elucidatory in this way: he who understands me finally recognizes them as nonsense, when he has climbed out through them, on them, over them. (He must so to speak throw away the ladder, after he has climbed up on it.) He must surmount these propositions; then he sees the world rightly. (6.54)
What, then, is one to make of these baffling sentences? How is it possible
to understand a work which concludes that its own propositions are
nonsense ? [...] And, moreover, what precisely does it mean to
‘throw away’ the ladder (of nonsensical sentences) in order to see the
world rightly?
We can see here the many "faces" of the book : the "foundational" side ("I’ve solved our problems finally", referring to the foundations of logic and mathematics) and at the same time a deceptivly simple semantics and ontology (we have to consider that in the 20's of the last century, the semantics of newly developed mathematical logic was far from clear).
But also the treatment of "traditional" philosophical topics : ethics, aesthetics, mysticism, solipsism, that were foreign to the Frege-Russell philosophy but were at the core of mainstream tradition : Kant, Schopenhauer, British Idealism.
And finally, the conundrum of the last sentences : a seemingly self-defeating assertion regarding the main Tractarian thesis themselves.
A useful recent book : Peter Sullivan & Michael Potter (editors), Wittgenstein's Tractatus: History and Interpretation, Oxford UP, 2013.