Worn-out plant. That's nothing new. Many breweries were still using clapped-out plant after WW II. Come to think of it, some carried on into the new millennium. Lack of investment - whether caused by external factors, such as the war, or the tight-fistedness of owners - was the root cause of the closure of many breweries in the 1950's and 1960's.
Fermentation has undergone changes. Nothing has produced a better draught beer than the Burton Union and the Yorkshire Square, though Edinburgh and some other centres have done admirably. But it seems reasonably certain that beers fermented in open vessels, all other things being equal, in most cases give a product more suitable for modern bottling owing to their more flattened condition. Scientific developments in pasteurisation may possibly alter this state of affairs. And some day a perfect pasteurisation may improve the keeping qualities on long ullage of draught ales, without detriment to flavour and character. One never knows. Some people think that draught ales will ultimately be wiped out. By your leave, never, if they have every ounce of skill, thought, scientific development, goodness of material and capital used in their production.
It is but 40 years since chilled and filtered beers were introduced. Now even Bass has found it necessary to present such beers to the public. (By the way, will Guinness ever be so bottled !) It is said that, in the long run, this great firm of Bass may find it essential to do all their bottled beers in this fashion. Not, to be hoped, while the present writer is alive. We may take comfort, a first-class naturally bottled pale ale won't die so easily. All the same, properly chilled, filtered and bottled, such ales have come to stay and to sell, Tempora mutantur, nos et mutamur in illis (not the writer). Price has a lot to do with the popularity of chilled beers, since they are generally lighter and sell cheaper."
"The Brewers' Journal 1940" page 55.
Open fermenters best for carbonated bottled beer? That's an interesting thought, if rather counter-intuitive. The praise for unions and Yorkshire squares is less unexpected.
"some day a perfect pasteurisation may improve the keeping qualities on long ullage of draught ales, without detriment to flavour and character" not happened yet, as far as I know. As for draught beer disappearing entirely - no-one would think that now. You have to put the authors remarks into context. There was a huge upsurge in bottled beer in the 1930's. One which fizzled out after the war as drinkers switched back to draught.
Will bottled Guinness ever be chilled and carbonated? Unfortunately yes. But not for another half century. One Pale Ale -White Shield - is still available naturally-conditioned. Just a shame there's no longer Bass Red Triangle