What's your opinion on "Fictional Earth" worlds?

[TV Tropes link.](https://tvtropes.org/pmwiki/pmwiki.php/Main/FictionalEarth) Fictional Earths are basically bizzaro versions of Earth that takes a lot of liberties with history and geography. They tend to have more substantial changes than alt history which usually have one specific point of divergence. Do you think they're lazy worldbuilding, or offer a lot of familiarity so worldbuilders can focus on the more important details?