2-column format has narrower columns, which means that your eyes move more vertically than horizontally while reading it. That is considered conducive to “skimming” long texts if you’re a “speed reader”.
Do you mean that you’re using AI as a search engine for your local bibliography? I haven’t seen any AI plugins for Zotero.
I feel like that's true when the font is insanely small, which I guess was good when people would print entire proceedings. Reading two column super small font on a computer is super annoying though tbh.
I'm severely dyslexic and the columns are a massive hindrance for me, and I also cannot skim read due to this and meares irlen. So my dislike is not universal applicable, just personal experience.
On the zotero front there a bunch of AI plugins. But I've not used them. But yes the premise is that your can speak and ask your library questions. Some are set up differently though. Personally I can fire a paper into an llm and get a good idea of the content immediately and then ask questions about it. It's more interactive and allows me to get a better idea of it prior to reading it.