There are a lot of pro audio tools available on Linux. I myself use some of the more basic tools, such as the universal plugin host Carla to host LV2/3, VST and LADSPA based audio plugins. And a basic lightweight MIDI mixing sftware called jack_mixer, combine that with a patchbay like qpwgraph, and virtual audio channels set up through pactl and I have a custom, lightweight but infinitely expandable plugin chain and mixer set up I can use for video recording and streaming.

But software ranges from that all the way to full featured integrated DAW setups and everything in between.