Teamfight tactics is basically a boardgame/cardgame. Nearly every single boardgame/cardgame is RNG mixed with tactics.
Even something like TCGs where people can build their own decks to suit them relies on RNG - if you get bad card draws all game you'll probably lose. And these players can spend £100s to get their perfect deck.
Even something more simple like Monopoly or Catan rely on RNG.
The fact is there is much more about it with having knowledge of the game, a game plan, and tactics.
If you go into a TFT game thinking "I'm gonna get a full Imperial team this game and my Draven will carry like mad", chances are you probably will lose early on.
Yeah it sucks if one player gets an early advantage by getting 4 items in the first 3 waves when you get none. However if you know you have a bad early game, you should try to continue losing until the next draft. You get extra gold for losing streaks and you can start building your bank and get more interest. You then also get first pick in the next draft giving you a HUGE advantage.
I've played quite a lot of TFT in the last few days and have noticed that very often someone who is at the bottom of the pile will, more often than not, make a massive comeback and end up wiping everyone.
An example of this is I literally just had a game now where I got down to 1hp by round 3. Couldn't win a single game, had a really shit team and barely any items. However being first pick in all the future drafts (as you can't get lower than 1hp) managed to let me completely change my team around. I went from a knight/ranger team into a 4 wilds, 3 shapeshifters, 2 dragons, and 3 scorcers by endgame (i also got 2 golden spaulas to give me an extra champ slot). Even though my team was mostly level 1/2 champs, there was absolutely nothing my enemy could do as I had way too much synergy.
The issue is most people playing TFT are Esports players who are so used to skill/teamwork winning games. However TFT is nothing like this and so it's frustrating a lot of people. In boardgames you have to plan multiple outcomes/multiple tactics, tunnelling down one path early isn't good.