[2020] Is it better to save to Steam Cloud or Hard drive?? why?

I've seen more cloud saves corrupt than non-cloud saves, though it's still so small an amount that it's more anecdotal than anything else.

Regardless of where you save though, doing like snowflitzer said and always saving as a new file is the best way to protect your city. If one save corrupts, you just lose some progress as you go back to the save before. Much better than losing everything because you only had one.

If you end up with a lot of saves, you can move the files out of the savegame folder and store them somewhere else on your computer as backups.