The Chrome dev tools alone are pretty incredible. Getting that much detail in your debug environment, paint cycles, render times, animation effects, and quick style experimentation is a huge deal.
The package ecosystem for JS is also an enormous advantage. Having access to data layer systems like Redux & the Redux dev tools, as well as any module designed to run on Node.js really helps ensure an actively developed ecosystem that abstracts more and more away from the end application developer.
Finally, I argue that performance bottlenecks are rarely an issue of the javascript. V8 is extremely fast and only getting faster. Most bottlenecks come from doing something dumb during rendering, or tying up a process reading from disk. These are issues that happen on all app platforms. The big difference is that Electron gives you to tools to effectively debug and optimize these, plus a HUGE wealth of online resources & tutorials to help new developers jankbust.