No, not really. You're making it sound like Classic MacOS applications were written in assembly, when it was mostly C++. Switching to Objective-C was more of a lateral move, not a clear step forward in time or level of abstraction.
The Mac OS X graphics stack was a pretty big change from Classic MacOS, but it wasn't that much of a change from NeXTSTEP, which worked with 12MB of RAM + 1.5MB VRAM. NeXTSTEP just wasn't as eye-catchingly colorful. Early OS X did poineer gratuitous use of some effects like translucency with blurs in desktop GUIs, but since this was the time period where GPUs were becoming mainstream, these effects weren't egregiously resource-intensive.
And considering that OS X was adapted with relative ease to power a smartphone with 128MB of RAM (with the graphical effects turned up to 11), it definitely wasn't fundamentally bloated in the way that today's Electron apps are.