As an observer (and satirist) of realities, Orwell was - reliable. Yet that is too weak a word (though he changed his views on some points, and in any case never posed as an ex cathedra pundit). A man of the Left, our champion in the Cold War, he, better than most of his contemporaries, could take in the phenomena, the actualities.
But theory, or abstraction, was - as Clive James has pointed out - not his forte. What he saw of the injustices of colonial rule was, at a more secondhand level, attributed to imperialist exploitation and the source of comparative Western prosperity - refuted as James points out, by the existence of Sweden, but anyhow untenable on various grounds.
More central to Orwell's work was his view that the poverty and distress he saw in England was attributable to capitalism, and would be cured by the socialist state. So he was indeed a keen advocate of Socialism - though definable (as he put it) as justice and liberty.
But at the same time he had little use for some socialists. His reason was that the idea of justice and liberty had been 'buried beneath layer after layer of doctrinaire priggishness, party squabbles and half-baked “progressivism” until it is like a diamond hidden under a mountain of dung'.
Even worse, 'The underlying motive of many Socialists, I believe, is simply a hypertrophied sense of order. The present state of affairs offends them not because it causes misery, still less because it makes freedom impossible, but because it is untidy . . .