As a player with 800+ hour, I can say that this is a free games with a lot of serious flaw. This contradict with what most people say "warframe is free to play done right".
Layer upon layer of RNG, means that you had to repeat a lot of the same activity to get the thing you need. The developer's decision.... sometimes you just can't agree with it.
The new player experience is really awful and rely on third party website to alleviate it. It has some good story, but is locked behind 100 hour+. They hardly take the effort to explain most mechanic in the game (like kuva lich, affinity distribution), so they expect you to search for wiki for everything.
At first, you were attracted by the fast paced third person shooter game; but eventually, it quickly become a looter shooter game, where the primary method to level up is crafting different weapon/warframe and max it.
In conclusion, this is a viable "free to play" game with some interesting concept and mechanic, but there are a lot of hidden feature / loot box that lurk once you get hook in.