I don't understand how Nintendo could even ship a game in 2020 that doesn't support some sort of cloud backup solution - especially a game where players are spending hours (months) building something, only to have it wiped out by hardware failure.

According to Polygon, Nintendo has now enabled a way to backup to the cloud:

Once you do, the game will backup to the cloud, even when you’re not playing. The last time your save has been backed up will now appear on the title screen in the bottom left corner.
In order to download the island backup, you have to contact Nintendo directly.

What? The game is one of the most popular games in 2020 across any platform, and you have to contact Nintendo in order to access your backup of your Animal Crossing island?

That's messed up.