Why is the ranked TFT RNG god-awful?

Ok I don't know if its just me, but the rng is complete garbage in this game, especially in ranked. I have so may games where I barely get any champs that I need to build my team while other players get 2 level 3's by round 3. The final strike for me was my last ranked game. i had a nasus, vayne, and senna all needing one more of each to be level 3. It was only round 3 so it wasn't hard to find them, and I had 42 coins saved to reroll. I spent it all and didn't get a single fuckin one. i then died because all the other players had at least 2 level 3's. This is honestly bullshit because like I said, this wasn't the only time this happened. Riot can you pls fix your broken luck system?