QtWebEngine comsumes significantly more CPU resource than other browsers

By other browsers, only Firefox and Chrome have been tested for now. But it should be enough since there are only Chromium-based and non-Chromium-based browsers now.

Accessing https://www.bing.com/ using both simple browser example and other browser and one can see obvious difference. The screenshot attached (bing_chat) if for Firefox using top command. Firefox uses ~40% and QtWebEngine + simplebroswer itself combined uses ~70%.

I blame the dynamic bing chat component for the numbers. So I also tested without bing chat. The numbers drop significantly, but still not comparable. See no_bing_chat.png. Firefox is about 0.3% and QtWebEngine is 4.3%. simplebrowser is not listed probably because it is around 0%.

Update:
Firefox may not be a suitable example since I was told that the process "Isolated Web Co" is also part of Firefox. So it combined with firefox consumes more CPU resources. But also, I received such numbers from customer:
[google-chrome]
chrome 66.8
gnome-shell 32.9
chrome 17.6

[simplebrowser]
simplebrowser 145.2
gnome-shell 51.2
QtWebEngineProc 15.3
So maybe it is still a valid issue, unless there are also dependency processes related to Chrome too?