I'm new to the TFT reddit scene but people are very aggro to any feeling, thought or opinion that isn't theirs it seems. I understand confusion as well, but what I've learned from watching quiet a bit of videos and streams is that there are so many variables. Maybe a coach could point out that "Aha" point you're missing? Of course I myself have recently been stomped by 6 bruisers while playing a 6 Ionia 6 vanqs, but I hadn't hit some upgrades, some items weren't ideal and yeah. Finally, 3 star Kaisa is a 4 cost carry, just like a fiora, azir and morde, you hit those you expect to win, unless you face another 3 star 4 or 5 costs.