Eizo makes a 1:1 26" 1920x1920 monitor. I've been tempted several times but the 1k price tag is keeping me off for now.
Looks like they also offer a 2048px square 28" for anyone willing to pay Air Traffic Control prices: https://www.eizoglobal.com/products/atc/sq2825/index.html#ta...
Also this is the first time I've ever seen a monitor brochure page be NSFW https://eizo-or.com/en/global/products/monitors/