[sc00ty]

I've dabbled with Kdenlive[0] and Shotcut[1]. They're cross platform desktop apps. I'm not sure how they would handle stickers/giphys, might be worth a try though.

[0] https://kdenlive.org/

[1] https://www.shotcut.org/

[xaxaxb]

I'd also add Olive[0] to the list.

[0] https://www.olivevideoeditor.org