There are a lot of falsehoods in your post.
First: no troops are limited to a particular event forever. When a troop is newly introduced, it’s available that week, then it is pulled again. 2-4 weeks after that, it appears in chests again. So they aren’t permanently exclusive, you just have to wait a while if you miss them.
Second: You’re young yet in the game if 250 keys per chest type were all you had! The weekly thread’s usually populated with people who spent many thousands of keys with nothing to show. That’s the nature of betting on 0.12% pulls. That won’t make you feel better, but it’s true.
Third: I don’t think what you are describing is bad luck. I think, from your descriptions so far, you are an early-game player and you don’t have an endgame war chest. That means it is expected that relatively early into an event you will hit a wall. The stats scale. They get stronger than your troops can ever get. So if you don’t have the most powerful troops in the game, you’re at a big disadvantage.
Fourth: if the devs actually “gave a leg up” to people they knew, I wouldn’t openly mock them as I do. The reason it seems like so many people are lucky is a very common psychological effect that F2P games foster: you see dozens and dozens of people who get lucky, but not the thousands and thousands of people who didn’t. Probably more than 90% of the game’s players don’t post at all, even in global chat, so you never hear about their struggles.