I'm sure you know but just to make sure. You can use Issue Templates to steer people towards Discussions. It's not perfect but it can help a bit at least.
Yes, we've got that and it does help a bit. But we're often forced to be heavy-handed and just close junk issues with a comment asking the poster to open a Discussions thread. I feel bad about doing that though as it's hard not to come across as unfriendly.