vlfi VS helm-ag

That is essentially what VLF[1] does in Emacs. It reads in discrete chunks of the file at a time and doesn’t load the next one till you try to display it. Doesn’t require any fancy data structures, just some extra book keeping and mechanics.

[1] https://github.com/m00natic/vlfi

That is an issue both related to Emacs' internal representation of buffers and modes working in the background on the data in buffers of very large files, for which there are some workarounds like vlf-mode. See for example (info "(emacs) Long Lines") for similar issues with long lines and a solution more similar to what all those other editors you mention are doing to mitigate the issue of large files and large lines.

You can edit gigabyte-large files with no trouble vlf.el https://github.com/m00natic/vlfi – though it's a bit of a separate universe, you have to use vlf-occur instead of occur to find matches over all gigabytes of the file

;; To have it offered when opening large files:

For arbitrarily large files (think GB) in terms of size of the data stored you may use e.g. vlfi.

You can use vlf package to open large files

You know how "there's an app for that" used to be a thing? Well, there's an elisp package for that: https://github.com/m00natic/vlfi

Theres always: https://github.com/m00natic/vlfi

I’m aware of a few potential solutions including: dired-async and async-shell-command. There’s also https://github.com/m00natic/vlfi for viewing large files, but I don’t know how to address GPG pinentry and TRAMP issues very well.

I think you might enjoy this mode: vlfi. It is available in the standard Elpa package listing.

Helm-Ag is wonderful.

I use https://github.com/emacsorphanage/helm-ag because searches the contents for all files in a directory. That uses ag, the siver searcher which is a variant of grep (which is a shell utility that searches file contents)

I'm not sure but maybe a tool like helm-ag or consult-ripgrep may help with this. You can interactively find lines that you need to edit, then move to edit-mode and batch rename some variables or smth.