You do realise the tier list is based around competitive play? So in a regular 4v4 mode she’s more than viable? This is literally why the tier list gets as much flak as it does because people use it like some unspoken law that because a hero isn’t S-tier they’re unusable. Do you go into a 4v4 mode and get 0 kills? No you don’t. Therefore she’s viable just play her regardless of tier lists for casual play because unless you’re in a 4v4 competitive match then it shouldn’t really matter.

Nobu needs a rework yet she’s the best character for holding the B point, cent needs a rework because his moveset is outdated yet you still see him picked because he can still contribute to the team with kills.

Valk is perfectly playable how she is now, all be it a few MINOR tweaks that she needs.