They're pointing to macOS and saying it uses 5 times less RAM there, but is 230MB for a weather app really something to be proud off?
The thing with ram is that once you can fit everything you want into the space you have available there is little benefit in optimizing further or getting more space. 1gig -> 230MB may be a large enough reduction that it goes from "too big" to "small enough".
Here is an example of one built using Real Basic on Mac Os system 7+. Probably uses less than 1MB.
https://tinkerdifferent.com/threads/snazzy-weather-a-snazzie...