Whichever way you’re sorting comments, default-expanded means that if you’re quickly perusing the thread and not committed to reading through the whole thing, you basically just get to read the first couple conversations, and those conversations aren’t necessarily the ones most relevant to you.
I don’t feel like the collapsed comments help with this issue, though—they just make it even less likely that I would read more comments, since reading them requires more work (additional clicks), and if I’m not already invested in it then I’m more likely to just shrug and go do something else after maybe reading a few of the top comments.
Trying to read collapsed comments feels actively annoying: if I was skimming them myself, my brain would automatically determine how much of it I wanted to read, and I could just skim through the whole comment in order to quickly see if there’s anything in it that looks interesting. Not being able to do either of those means that I need to first expand the comment in order to determine whether it’s worth reading. (The only exception to that is if it was a part of a subthread which I’d already determined was uninteresting—in which case I would have used the “hide subthread” feature already.)
I don’t feel like the collapsed comments help with this issue, though—they just make it even less likely that I would read more comments, since reading them requires more work (additional clicks), and if I’m not already invested in it then I’m more likely to just shrug and go do something else after maybe reading a few of the top comments.
Trying to read collapsed comments feels actively annoying: if I was skimming them myself, my brain would automatically determine how much of it I wanted to read, and I could just skim through the whole comment in order to quickly see if there’s anything in it that looks interesting. Not being able to do either of those means that I need to first expand the comment in order to determine whether it’s worth reading. (The only exception to that is if it was a part of a subthread which I’d already determined was uninteresting—in which case I would have used the “hide subthread” feature already.)