It's hard to tell with just these scraps of evidence, but absence of Vic does not mean presence of happiness. Eliot was an accomplished poet in his own right. The poetry might have been different, but the interests and vision probably would have been the same. He was focussed on the lower class and not just for entertainment as seemed the case with Vic.
P. M.

John Angell Grant <[log in to unmask]> wrote:

No Vivien, no Waste Land.

It's been said before, but it's said again in this review of col. 4 of the letters:

In a rare newspaper interview in 1994, Valerie Eliot said that her husband wrote The Waste Land because Vivian made him suffer. “We owe the poem to her, no question: he wouldn’t have written it if she hadn’t given him such hell.” And in oblique confirmation of this claim, in a letter included here, discussing The Waste Land with E M Forster on August 10 1929, Eliot says: “You exaggerate the importance of the War… The Waste Land might have been just the same without the War.” It is perhaps not surprising that during the last near-decade of Eliot’s life when his second marriage gave him unprecedented happiness that his creative output diminished accordingly.