Thoughts on Warframe in general?

is it even worth it to start playing this?
From what I can tell it seems one of those games that you have to spend a lot of money just to be on par with everyone that has been playing since launch

The game is a fucking trainwreck right now. Their refusal to fix core design problems has finally bit them in the ass.

I haven't played this game in a while but why is Valkyr bad?
I had a build for her with Warcry+Eternal War. Paired with Umbral Fiber and a whip, you were tanky as fuck while fast as fuck and you could just whip everything to death.
I can't actually think of a "bad" frame. Baruuk is probably the worst one if I had to pick one only because I don't think any of his abilities fills a niche.

Spending plat should only really be used on cosmetics, everything else can be acquired through playing the game.
That being said, new-player experience is absolute ass unless you have some seasoned player guiding you in some way.