WW3 is just beginning and you're worried about what shape the planet is?
Absolutely!
A wise man understands the implications of a worldwide deception. Just for starters, it suggests that the world leaders are more "together" than they appear -- which means that the wars and bloody conflicts we observe are only done on purpose, to depopulate. So a sane Catholic man, possessing the truth, would arrive at a DIFFERENT conclusion than his sleeping, sheeple peers:
don't get involved, don't get caught up in patriotic hysteria, don't enlist. But if you don't KNOW that we're all conquered, our minds imprisoned and deceived -- then you might sign up and get caught up in every trend, movement and zeitgeist.
So yes, the truth about this ABSOLUTELY matters.
And if the earth is flat under a dome, then there 100% has to be a creator. The whole framework for atheistic random-chance-plus-billions-of-years evolution REQUIRES a big bang, spinning disks of gas coalescing into suns, the debris coalescing into "planets" orbiting around those suns, and then Abiogenesis creates life (which has never been observed EVER, but whatever...). Humans are then nothing special.
So yes, it DOES matter.
Those why deny the globe earth are deist or spiritual AT WORST. Globers are satanic at worst.