You can do this with mpv. It's an open source cross platform media player.
For example, here's how I set up a tiny Lua script extension[0] to be able to visually cut videos in an intuitive way. It does it in seconds without re-rendering the video by shelling out to ffmpeg.
Years ago I did the same thing with a shell script CLI tool[1], but mpv's visual aspect makes it so much faster and easier to make clips out of a longer video.
[0]: https://nickjanetakis.com/blog/visually-create-video-clips-w...
[1]: https://nickjanetakis.com/blog/create-video-clips-with-ffmpe...