Ardour is definitely professional grade, but I must say that it’s far from simple to setup. First, you may not have the latest version available in you SW repository and you would have to compile it yourself! Then, despite all the progress brought by pipewire, audio config in Linux is complicated and unreliable, especially for this time of work, requiring different audio devices, MIDI control interfaces and VSTs.
I am not an audio professional, I’m an amateur, and found myself demotivated by the amount of work required until I am ready to create music, and finally gave up :(
I feel like outdated software on the stable distro like Debian has become less of a problem with the development of flatpak.