This kills the joke, but:
It's all a stage play. SMB3 was the first (and maybe only) game to come out and say this outright, but it makes too much sense in all the others as well. That's why everyone is still friends and goes out go-karting and playing golf and tennis on the weekends. That's why we've "defeated" Bowser two dozen times including dropping him into literal magma and then he's back again next game.
No one was ever in danger, it's just, soap operas are the main export of the Mushroom Kingdom. They sold us a story about love, danger, and the fury of a righteous man, and we've been eating up the sequels for 30 years. It's Mushroom Kingdom Star Wars.
