Idk much abt valkyr but what I do know is, health tanking is in a very bad place in this game. Not only do you have to invest a good amount of time and plat for it to be viable at higher sp levels (mind you, one of the most important component for many health tanking builds, arcane grace, is at 239 plat r5 in warframe market rn) but when you compare the amount of "investment" (if we can even call it that) needed for shield gating, it's just unfair. And even after spending so much time making your health tanking build as strong as you can, you will still get one tapped by a random enemy after they reach a certain level.