Ah, that's a good point. I'm sorry not to have a better solution at the moment.
One thing I think we'll do is add links to comments to jump to next subthread (and jump to parent), which would at least enable you to skip the noise easily.
html5's summary/detail works without javascript, can be controlled via attributes and remains interactive with JS disabled. Maybe with some creative CSS it could be somehow wrangled into the [-]?
Summary/details are very difficult to style. You can approximate it using some hackery with a checkbox and sibling selectors. Here's an example that I was working on recently: https://smichel17.gitlab.io/donate
Note: accessibility is still WIP, because the toggle is not selectable with the keyboard. Should be solve-able though by hiding the checkbox via different means than `display: hidden` (ie, so the checkbox is visually hidden but still keyboard-selectable).
One thing I think we'll do is add links to comments to jump to next subthread (and jump to parent), which would at least enable you to skip the noise easily.