Probably the most mature resolution. They're breaking things off to cut the cycle of self destruction but there's hope they can grow and eventually reunite in a healthy way.
Glad she didn't commit suicide and there wasn't anything more insane. They just mutually understood each others' flaws and that they're not what each other needs at the moment.
And this is why I always believed in Kanon. She never wanted Izumi to have a bad life at all. She was just trying to do things for him in the only way she knew how. It's not her fault she wasn't equipped with the right tools for the job.
In this chapter she immediately understands Izumi actually cares about his friends and he's not the same as her, and that really redeemed her for me. Especially how she didn't push for him to commit suicide with her. She still has compassion left. It's just that in her eyes, her time was up, but his wasn't. Though thankfully Izumi helped her see that her time doesn't have to be up, there's still a future for her.
I'm happy with this conclusion, and I really hope we get an epilogue for them later on where we see they're together again as adults.