Adding one more vote for this! Seems like there were a few feature requests in 2020 for a similar function, Now it’s all tracked in this thread?
I’m not even using multiple monitors, just one big one. It’s easier for my brain to be able to visually separate ideas and move them around on the screen.
My work-around is using a seperate markdown editor (Typora, Mark Text) to open individual files for viewing or editing outside of my vault window. The downside is losing some of the functionality of Obsidian, like hotkeys and plugins, meaning I sometimes have to jump into the same note from Mark Text to Obsidian if I’m doing more than just writing text.
Edit to add: I have considered making a vault from a subfolder to have two Obsidian instances open, but it would be nice to avoid that.