No one will ever know with 100% certainty but believing in reincarnation with 100% certainty is a much healthier world view. When you see the world as a 1 life prison planet, you’re more likely to feel disempowered and treat others and the planet worse. When you see everyone as someone to learn from, a potential brother/sister/parent in past or future lives, you’re more likely to treat them better. When you see this planet as a potential home in future lives you feel a stronger responsibility to treat it well.
The people who give into fear and doomer narratives aren’t empowered, they’re less likely to be kind, less likely to show love, and more likely to act in the short term mindset that plagues modern society.
Everyone can believe what they want but I choose the uplifting mindset because or beliefs shape our behaviors.