VSCode is actually one of the best for large files. Not as good as Sublime Text, but it can happily edit million line files, and you'd be surprised how many other editors can't do that. Zed couldn't until recently (not sure if it can now; I haven't checked recently).
Once you get into the GB range there are very very few editors that can edit those files unfortunately.
I have to turn off my config (-u NONE) for large files (e.g., multi-GB JSON files), or everything slows to a crawl. I never profiled it to know what's causing the slowdown. It might be treesitter.
Once you get into the GB range there are very very few editors that can edit those files unfortunately.