Worldbuilding

In my alternate history world (see my profile), I wanted to let African and American cultures thrive, not be colonised by Europe.

I wanted transatlantic contact to be contact between equals: West Africans + East Americans + far West European barbarians (distinct from the imperial core in Central Europe) all come together and ally... it's not exactly a lovefest but they see their common interest and create technology-transfer and confederation.

In actual history, one reason America was wiped out was the West lacked immunity to smallpox.

Then I learned a little-known historical tidbit (learned it on Hexbear iirc).... Africans had knowledge of smallpox inoculation! Therefore, if Africans were respected allies that crossed the Atlantic (not slaves), they could bring the Americans smallpox immunity:

• https://en.wikipedia.org/wiki/Onesimus_(Bostonian) – Onesimus (late 1600s–1700s) was an African (likely Akan) man who was instrumental in the mitigation of smallpox in Boston, Massachusetts. He introduced the variolation method of inoculation, which prevented smallpox and laid the foundation for vaccines.
• https://en.wikipedia.org/wiki/Smallpox_vaccine – Variolation was also practiced throughout the latter half of the 17th century by physicians in Turkey, Persia, and Africa. In 1714 and 1716, two reports of the Ottoman Empire Turkish method of inoculation were made to the Royal Society in England, by Emmanuel Timoni, a doctor affiliated with the British Embassy in Constantinople, and Giacomo Pylarini. Source material tells us on Lady Mary Wortley Montagu; "When Lady Mary was in the Ottoman Empire, she discovered the local practice of inoculation against smallpox called variolation."

So in the alternate history, in the 1490s Europe crosses the Atlantic and rounds Cape Bojador, and a multi-ethnic confederation initiates contact with the Native Americans. It brings the knowledge of smallpox immunity to them, because that's a technology several Old World Cultures (but not white Europeans) had.

By making Africans equals in transatlantic contact, that simultanæously justifies why Americans weren't decimated by smallpox.

"it's magic, I don't gotta explain shit" is the single most helpful phrase in world building

The eruption of the giant volcano that was non-colonialism non-genocide solution to having a continent wide mostly intact ruins full of stuff probably killed way more birds than that.

Why bother shipping all those raw materials, chemicals and minerals across the space between planets when you can just use various engineered bacteria to grow them in vats on location?

This also justifies the inclusion of various tubes, flasks and vials full of colorful goo that does stuff, a vital element of all science fiction.

Solving pretty much all the colonialist "raid the primitive people's temples and steal their stuff" Gygaxian bullshit that was baked into the game concept by having the adventurers invited as guests into distant lands, working with the locals to solve problems, and receiving gifts of gratitude as the treasure table instead of looting.

They even visited those temples as guests, met their actual living gods, and chilled with them, even partied with them.

For all of its faults and flaws (the post-main-story Stormblood story-driven proposal to take all the looted wealth of Ala Mhigo and hand it over to a fucking corporation as an investment instead of giving it back to the people was agonizing) FFXIV had a pretty decent idea with Dawntrail, where a distant land invites your character and your adventurer companions over to learn the culture and work with it rather than invade it.