I recently learnt of the 21:9 ratio screens, or as many are commonly called, Ultra-Wide displays. Almost all Ultra-Wide displays however are low in pixel count. Yes, some are 5K on width, but more often than not, they are only 1440 pixels on the height, which is less than what a 4K display offers.
The MSI Prestige PS341WU 5K2K Monitor is interesting because it offers 5K resolution on the width, and 2K resolution on the height, (5120 x 2160) unlike almost every other Ultra-Wide monitor on the market. This essentially makes it a 4K monitor, with an extra 3 million pixels off to the side. Some call it a 4K Ultra-Wide, and that is probably the most appropriate name, and it is exactly what I have desired for some time. Somehow, I missed the announcement of this monitor when it was released back in 2019 along with the only other monitor of its type, and the display it is based on, the LG 34WK95U. (I have now seen a new Dell 5K2K monitor which has been released very recently)