Earlier quoted context omitted.
Try looking at the source of the page. There's no way in hell anyone would call that "just" the data necessary to convey the information. The site is also unusable on mobile, because ASCII art unlike proper semantic HTML is not easily rescalable by the browser. And it's inaccessible by users relying on screen readers, ironically because of all the ASCII cruft.
On iOS the page scales as expected. The only visual glitch with columns not matching up is something I'm getting on non-zoomed desktop as well. Presumably this is from specific source text of as-of-yet unexpected lengths not being handled properly during calculation of the maximum columns. The accessibility issue would be resolved by using workarounds typical of screen-reader solutions: ARIA markup, tricks like Boots…
Bootstrap's screens reader only classes are somewhat of a hack, and does the opposite of what you're suggesting anyway (aria-hidden is the proper way to go, but as you said that will mean adding a ridiculous amount of markup to the page), while images support screen readers natively via the alt attribute - no messy markup needed.