It's relative. Outlook is using 2.37 GB of RAM as I type this.
Granted, that's reserved memory, but that's the only memory you really need to worry about anyway.
Of course, native doesn't make a program automatically use less RAM. It does start with a lower footprint through, meaning that you can keep an eye on memory usage without relying on ugly hacks in your code.
$ ps -eo rss,cmd |grep claws-mail|grep -v grep
36016 claws-mail
37 MB, 4 accounts open, one of them holding ~10.000 messages (i.e. which need to be archived but it not being my account I'm not the one to do so)Developers shouldn't be assuming that their users will have machines even close to theirs spec-wise.
Chrome is awful with resource usage to begin with, which is why Electron is, it bundles and runs a headless Chrome for each Electron app.