Slack is an electron app which is why it needs GBs to run. Native apps can run in a fraction of that. But the faster time to market is likely most bloated implementation.

That's garbage collection for you. Typical GC programs want all the memory there is, just to be able to sweep less often.

From my experiments with the JVM that is not really true. Keeping memory usage below 1GB is pretty easy. It's only getting tricky when you want to go below 200MB. You'll have to deal with the overhead the JVM introduces. As a result I often just use lua for really simple programs and I am rewarded by creating programs that use less than 2MB of RAM.

Which Lua kind/runtime you're using that give you such frugal programs? I'm intrigued (pun with your name intended).

Or good old Minecraft with 300 mods. It takes 20 minutes to start and even if you run the server embedded within the Minecraft client it will take 6GB at a minimum. Well, RAM is cheap so I just bought 32GB for $110 out of necessity but I still keep paying attention to how much RAM my programs need and avoid wasting it needlessly (using 4.6GB out of 32GB right now).