Seeking a text editor that can compare 2 files and let you edit either of them on-screen with immediate comparison updates

Kate. Zed. Basically anything with Git's diff doesn't seem to allow live edits to either file directly in the comparison itself; I have to open one of the files in another text editor and search for the discrepant lines manually. Is there anything that can rival VSCodium out there (which, yes, has no telemetry but still feels too resource-heavy relative to the Syncthing sync-conflicts for which I intermittently use it to manually resolve)?

The search has gotten so bad that it feels like a failure to have to download Notepad++ on Windows to try to run it through Bottles, in which I then had a graphical scaling error (had to restart with 200% DPI, but the mouse cursor is still tiny) and I couldn't open my own Linux user directory in its file browser.

I'm pulling my hair out; I had no idea that this would be such a ridiculously difficult search. I'm trying NeoVim next, with possibly LazyVim, but I fear the same outcome...