I always feel like it is my fault when I die in Slay the Spire, Risk of Rain 2, Downwell, and Enter the Gungeon. But I think we're saying the same thing.
When I died early on in these games, I did not know how to avoid it but felt like I could if I knew how, so I still did not blame the game.
Some of your patterns gave me the feeling that it was impossible to avoid at all. Still issue, probably, but the feeling was different for me.
I agree calibrating that skill curve in 7 days would be roughly impossible.
Edit: I agree with your skill curve analysis though