One way produces far more wealth for more people than the other. Wealth isn't just luxuries, it's technology. It's health. It's more time to do more things more efficiently. It's evolving and generally improving the human condition, as opposed to stagnation. Obviously not everyone agrees with the direction of evolution or the various philosophies involved, but the system provides flexibility such that we aren't constantly genociding each other just to get our way, which used to be the norm. Of course at the end of the day none of us know the meaning of existence, but I think most can agree taht "reducing fruitless suffering" is a better place to start than most.
Obviously there's a balance to be struck. 100% individualism is just anarchy. But history has proven that allowing people an above-historical-average level of individual freedom leads to a more productive and secure society.
That said it's debatable whether strong-man dictatorships are "collectivist" at all. They're extremely individualist, but only for a select group of elite individuals. Otherwise they'd try and make decisions to benefit the group, and as Putin has shown in Ukraine, they often don't. Never mind the strategic decision to invade which might have had some initial merit, you would expect a truly collectivist nation to prioritize competence in its military. As it stands a full NATO conventional intervention could end the war in a month, the only thing keeping Russia intact is brutal suppression of internal dissent and a nuclear arsenal that, if it's been maintained as badly as its regular military, might very well explode in its silos on launch.
That doesn't sound like a very effective collective to me. Maybe it would have been effective 300 years ago because that level of organization is all most nations had, but that's the point. It's an obsolete model.