Most of Yasuo's problems could be solved with one simple yet crazy change...
"Yasuo's basic attack crits no longer proc on-hit bonus effects."
Think about it. This kills Frozen Mallet on Yas, Triforce on Yas, he can no longer perma-on-hit you, he can no longer build BoRK and shred you, and he actually has to Q to proc Phantom Dancer.
Of course, this seems like a huge itemization blow to Yasuo and maybe he would need some adjustments, but he would be a lot less annoying with this change alone, judging by how many of his problems are his interactions with items.
Just a thought.
EDIT: Lifesteal does not count as a bonus on-hit in this case. So Yasuo will not lose lifesteal on his crits.
main detected.