There's a clear trend between Play rate & Nerf Rate
Title.
Example:
Lee & Yasuo; get played a lot, been strong for a really long time. Are they going to get nerfed? No, because their play rate is just too high, & riot can't disappoint them lee/yas mains
However, Taking Taliyah as an example, nobody plays her so it's okay if she gets trashed. I mean she's been underpowered since 6.14. probs even before that... but riot pay less attention to her because no one plays her as much
I main diana, and I know her play rate isn't high, which is why when I open up the latest patch notes, I'm never surprised if she doesn't get polished with bug fixes, or a buff.