Yeah FTL's problem is that once you fall behind in the game's economy, if you will, there's only very limited ability to take it easy and try to catch up,
but it lets you avoid a lot of combat so it's possible to limp along almost-losing all the way to the end (or damn close) and reach the boss in such a state that you can hardly scratch it. The trouble is that if you aren't able to handle encounters, you're already toast, because you
need to be handily winning most encounters to stay ahead in the game-economy. If you're avoiding fights out of necessity, you're likely doomed—which is part of what I meant about playing-to-limp-as-far-as-possible and playing-to-win looking very different, so the former not even being very useful practice for the latter.
IIRC (it's been a while) the luck component in it is also largely negative, in that bad things can randomly happen to you but (substantial) good random effects are minor and unusual, so you can't even luck your way into enough resources to have a hope of winning, as in something like Nethack where a desperate prayer or drink at a fountain or something might totally turn your game around. If you're more than very slightly behind, the game's not going to hand you enough to salvage your run, period.
I think part of the trouble is the illusion-of-choice map system. In reality, you have to be taking certain routes to do well, by deliberately seeking encounters, et c. The illusion is that you can take an easy route through an area and still be on a path to victory. IMO the maps are kinda pointless in that game, given how the mechanics work, basically just providing an opportunity to fuck up without knowing it, and also permitting the limping-to-the-end-but-long-ago-doomed effect.
I find FTL frustrating because I like some aspects of it but IMO it makes some major mistakes in terms of game mechanics, to a degree that I find it hard to appreciate the things I like (mainly the tactical combat minigame). I get what they were trying to do with the rest of it—the time pressure cutting off options and forcing choices, et c—but it doesn't all come together correctly. Needed one more conceptual pass to make it all fit properly, which is even more frustrating when it's not that complex a game. All that effort to finish it, but fundamental flaws left in place throughout.