As far as I recall, Anchor was bankrupt when it closed in 1926, and the site was bought by the Dublin Corporation in 1933. We'd seen elsewhere that breweries, like Manders (off James' Street), went out of business due to price cutting and, I think, certain breweries not complying with pricing agreements maybe accelerating that demise. There's still so much to check out, but at least Dublin seems well documented.
What we've also read and heard is that many of the smaller breweries became bottlers of Guinness Stout, as the canal system opened up transport, and the locally produced beers could no longer compete with Guinness (either because they were able to do it cheaper due to mass production, or the locals wanted a bit of exotic, or is was simply better).