I've noticed that github doesn't expand large files (like package-lock.json) by default, while gerrit does.
My usual workflow (in gerrit) is to open a patch and click Expand All. It works great, unless there's a package-lock.json file. Then the page becomes unresponsive for a while (while the huge package-lock.json is rendered), and any files under it are not rendered, even after package-lock.json is.
Maybe it makes sense to expand some files, but package-lock.json is not supposed to be edited by humans, so it's very unlikely that you would actually want to review the file.