I ran minimalist Void Linux on a crappy dual-core Celeron Chromebox with 2GB (yes, two) of memory as a workstation for a few weeks last year.

It was impractical longer term, but really, as long as I didn't open more than a couple Surf (the Suckless browser, uses the Webkit engine) windows at a time it didn't feel slower than a tricked-out Mac or a beast of a Windows machine, for everything else. Amazing what running as little JS as possible can do. I had to run Docker and VMs elsewhere since they hog memory by design, but it was entirely fine as code-editing and command line workstation. A heavy IDE for, say, Java might have been painful if I'd needed that—which is kind of crazy, because those used to run just fine on well under 1GB of memory, too.

Using Void helped a lot because a bunch of the background garbage on something like Ubuntu, which is really getting out of control, wasn't hanging around eating memory and periodically waking up to burn cycles for unclear reasons. I imagine the benefits of Haiku are similar (big fan of BeOS back in the day, thing's UI responsiveness on mediocre hardware was downright magical)