We save them for our kids to wear to school on Election Day.
In California, this used to vary by county. Some counties provided postage-paid envelopes for returning ballots, other counties (including my own) required stamps. A few years ago the state legislature passed a law which requires all counties to provide postage-paid envelopes.

In Washington State, there is no need to request a ballot. Everyone gets one in the mail. And, as I recall, you can drop it in a drop off box or mail it postage prepaid. No stamps involved
Same in Colorado. They just come in the mail for where I’m registered to vote. It’s easy as it should be.
I think in Colorado, you do need stamps. But there are plenty of drop off boxes where you don’t. This should be pre-paid - no stamp necessary. “Bueller? Bueller?”

Still have whoever is elected President as the favorite for 2024, and the first woman and first black person on the moon (assuming (a) the mission is successful and (b) the Chinese don’t get there first) for 2025.
Did I say to pencil in the moon landing for 2025? Better break out the eraser…
NASA’s Artemis III astronaut moon landing delayed to at least September 2026 | CNN
I’ll take “What happened in 2028?” for 200 Alex