Out of all the open source programs, Ardour definitely is the most capable one currently. LMMS fills a niche of chiptune, but seemed inferior in every other way when I tried it.

If you are just concerned using linux but are open to closed source software, bitwig is the way to go probably. It's pretty much made by the old Ableton team.

If you want to make digital orchestral music specifically, Musescore 4 with musesounds is the best option, as they are the only program not limited by MIDI. And who knows, maybe Audacity will become more capable more quickly once they're done with their refactoring.

NB: You can absolutely develop a pipeline where you make certain things in one program and export what you did in another program.