If you don't know how to manipulate RNG then I can understand why it wouldn't be fun for you. Part of what makes strategy fun is learning the game's mechanics enough to be able to win regardless of how the game is played.
Critical damage for example is RNG. 100% RNG. yet many games use it and a ton of players abuse it because they know how and it's usually something along the lines of... stack it to 100%. If no one had told you that yasuo phantom dancer + IE was broken back in season 6 could you have figured it out on your own? personally i'd like to think so. TFT is similar. Yes there are some things that seem broken, random, and completely uncontrollable at first glance, but with enough understanding of the game's mechanics a player can abuse those mechanics and learn how to adapt should the need arise.
It's a game for thinkers. people that want to have a wrench thrown into their plans from time to time. it's boring being an overlord if you have no one to try and stop you from time to time.
Yes, I will admit sometimes it's annoying when you can't get what you want, but if you go back and look at what you were given sometimes you see that what you were given is usually something else that you could have done to improve your next game. it's similar to how magic the gathering draft pick decks work.