If you are optimizing while playing, you'll have 2 upgrades by Front 2 that increase a single prep move. That will give you 3 boon dice (1 you start with & +2 from the upgrades), and rolling 3 dice only has a 12.5% chance of only getting a 1, 2 or 3 as your highest. Add in 1 bane die from the front danger level and the odds get a little worse (around ~32% i think, but would need to recalculate it), and that's not including any special move rerolls.
But yes, I won't deny that it can be a game that feels difficult to beat the kaiju! Emerging completely unscathed is really difficult, and that's the intent of the design: what will your pilot do when the odds are stacked against them? Which parts of your worldbuilding will be destroyed, and what will remain in the ashes?
It's a game that asks you to be ok with losing these things, and still finding the story within it. It's not something that everyone enjoys.