Why software written in C++ Qt are more energy efficient?

I have been using software written in Qt [0] across different OS. Many of them were written specifically to be used in GNU/Linux, such as Okular [1] and QBittorren [2]. Others, such as VLC [3], were later shipped to other OS. In the case of VLC, only the GUI was written in Qt.

I have noticed that Okular and Qbittorrent were very energy efficient in GNU/Linux. But I didn't expect it to be the case in other OS such as MacOS.

Recently, I used Homebrew to install Okular on MacOS, and I compared it to other PDF readers such as Adobe Acrobat Reader and Skim. Okular was superior in terms of energy consumption.

RESULTS: Energy impact for 12h:

Adobe Acrobat Reader = 0.9

Okular = 0.4

QUESTIONs: Is this always true? Do Qt software always perform good in terms of energy consumption, across OS? Why is that?

[0] https://en.wikipedia.org/wiki/Qt_(software)

[1] https://en.wikipedia.org/wiki/Okular

[2] https://en.wikipedia.org/wiki/QBittorrent

[3] https://en.wikipedia.org/wiki/VLC_media_player