+1

I tried to switch to FF on multiple occasions, but it's a CPU hog on MacBook. Why is this issue ignored for so long?

"Resource consumption" in the parent comment refers to power efficiency, specifically GPU blits. That issue has not been ignored. I don't know what "CPU hog" refers to; the issue is not about CPU usage.

It's consuming ~20% CPU in idle on my machine (MacBook Pro Retina, 13-inch, Early 2015, 2.7 GHz Intel Core i5, 8 GB 1867 MHz DDR3, macOS Mojave 10.14.6)

Based on what I saw the last time I checked Mozilla's bug tracker, the issue has a low priority and no one is actively working to resolve it.

From what I understand, it's a low level rendering issue.

That's not true. There was a roadmap posted yesterday and patches to begin to address the issue landed this week, including a new preference to opt into Core Animation. This is Markus' top priority at present. https://bugzilla.mozilla.org/show_bug.cgi?id=1429522

Source: I wrote the initial version of those patches, though I think Markus has basically rewritten them all at this point.

My mistake, I hadn't checked on the status in nearly a year. Glad to hear that progress is being made. Thanks for the update and patches!