Ardour is not as focused on "in the box composition" (i.e. making music entirely on your computer) as Live or Bitwig are. It originated as something closer to ProTools or Logic or Digital Performer in the sense that it was focused on recording people doing stuff (blowing,hitting,singing,speaker,scraping etc. etc).

However, in recent years, we've added a lot of the stuff you need for "in the box composition" and many people do use it that way. There's (always) more to do, but it's fairly capable in this sort of workflow now too and will continue to improve over time.

Ardour has been around for more than 25 years.

Please be aware that almost any fully-capable DAW (everything named here except lmms) has a steep, challenging learning curve. Don't jump in thinking it will be easy.

Similar but not quite. One of the problems that you might face is a lot of tutorials are for Ableton, Logic, Cubase etc. It shouldn't actually matter, but you might find it confusing what you can and cant do if you are following what someone else is doing in another program. It’s like learning C# from a Java course. Once you understand the fundamentals it does not matter what you use within reason.

But I’ve used Ardour a long time ago and I don’t see why you couldn’t release music with it. Another alternative is Reaper.

if you mean you just want to make music and arent too bothered about recording then Cardinal is a free modular eurorack synth you could mess around with

or you use a VST host like Kushview's Element and load up on all the free VST instruments and effects that are out there. you would just need a midi keyboard hooked to it then or use Cardinal to generate note patterns

https://cardinal.kx.studio

https://kushview.net/element

or something like Orca if you want to go off the deep end!

https://github.com/hundredrabbits/Orca