Do I need a real keyboard, drum machine and other instruments to make music, or do you think software nowadays are able to generate the same sound?
What would be the difference, and would the quality not be the same if it was made by software?
Let's separate out 'synthesised' music first.
If that's what you want to do, then true realism is not on your list of needs.
Computer-based synthesisers & drum 'machines' are just as capable, if not in some cases more capable, than their hardware equivalents.
If you want to 'fake' real instruments, then with current technology it is just about possible. It does, however, require a good amount of skill to take a sample set & make it feel real. If you play it like a keyboard, it will sound like a keyboard.
There is still a great deal of 'performance' required to be convincing; even if that performance can be tweaked note by note after the initial recording.
Over the years I have made a fair living out of being able to fake some aspects of 'real music'. I've uploaded a few short stems from a "60's style" album I did a while ago for a library company, as part of a larger project.
Not a real instrument in sight - though bear in mind that in a mix they get more convincing.
Naked, you can tell the difference.
I hope this isn't seen as too much of a plug for my own work - it's really just the best way I can think of to throw out a range of examples in one easy bite.
This is my "TV Composer" showreel - a dozen different styles, all entirely made in the computer, no real instruments anywhere.
Software can certainly produce the same sounds as a drum MACHINE. Maybe not the same as a real drummer on real drums though!
Synthesis and samples are getting pretty good. But somehow, the people with the money still book real players with real instruments for a lot of things. And if the computer did it just as well, they wouldn't spend the money!
Does that answer your question?
Computers can use any sound generation technique that a digital synthesizer or drum machine can use - so there is not any fundamental difference in quality.
It might be that a particular hardware drum machine or keyboard has facilities that you can't find in software, but of course the reverse might also be true.
A hardware keyboard might be able to achieve lower latency when playing, and it might also be more reliable or stable than a general-purpose computer system.
Some people might consider that analogue synthesizers and drum machines can't be perfectly simulated in software.
To me it is faster and more accurate to play things into the computer rather than using the mouse to input notes and then tweaking timing and velocity etc. to make it sound human. I use a drum machine and a real synth along with VSTs and a midi controller keyboard. Each has advantages. I like using the VSTs because I can easily add a wider variety of fx and even change to a different synth, so a bigger box of crayons in my mind. The hardware one is old reliable, I know how to get favorite sounds from it and sometimes I don't want to fire up everything and get all DAW intensive, so I have the option to simplify and just record into the drum machine (actually an MPC Live, not fair to just call it a drum machine).
The set of possible interactions is definitely important for learning and the creative process. That's the set of "can do" vs "cannot do", and "what happens if I do x". Very few if any physical guitars or violins offer you the possibility to change the mode of operation from "playing" to "checking if there's any very important activity on music.stackexchange.com". And quite often, physical instruments make physical waves that naturally vibrate the air in the same physical room that your physical body is in. It's more natural.
Have you seen the artist called Brushy One String?
Inspired by that instrument and the music he makes with it, I made a one-string from an old acoustic guitar, removing all but the A string. It was surprising how it changed things. There's only one string, so you focus on very basic aspects of accompaniment. No chords, no melody, just a bass groove that implies some harmonic and rhythmic barebone essentials. Furthermore, my kids who had been a bit reluctant to try playing the guitar just for fun, took the funny one-string and started making music with it. I think that might be due to the one-string having fewer implied social requirements and demands, how to do it "correctly", and because there are just fewer parts, so you're more free to concentrate and toy with it. It feels less frightening and more accessible.
To answer your question: there are many ways to create music. A motivated and skilled person can create good music with anything. An unmotivated and unskilled person cannot create good music with anything. Software or hardware. Focus on your motivation and skills. Start with something that lets you focus and learn. Simple physical single-purpose devices are good.
Software is compared according to its "features". More features is usually better for sales, but the more features there are seemingly at your disposal, the more it demands from the user. Are you in control of the instrument, or is the instrument in control of you?
Wave samples are called vst (virtual studio technology), there are professional samplings of symphony orchestras as the vienna symphony orchestra library or the Iconica library Funkhaus Berlin: Iconica Sections & Players brings exceptional modern orchestral expression to every composer. Featuring over 145 GB of strings, brass, woodwinds, percussion, and harp samples, with a huge variety of expressions and articulations, the advanced, user-friendly interface makes it very intuitive to use, speeding and inspiring new composition. Recorded in the legendary Funkhaus Berlin with partner Orchestral Tools, it is the ideal composition tool for movie scores, classical music, pop, rock, jazz or hip hop.
The job of composing and arranging however is not finished by adressing a voice to an instrument or choosing a vst instrument for a layer or a channel. Similar to the first synthesizers were the keyboarder had to modulate the attack, delay, sustain and release you have to control the sound for the performance depending of the length of a tone, the style of a piece and all kind of dynamic aspects, what a musician of flesh and blood is doing intuitively, all this even the samples have been taken of various pitches and all kind of attacos and dynamic parameters.
Like the perfect layout - compared with a manuscript - this manipulations of the sound can become infintely.
Thats why - probably most demos of this vst are composed of short notes.
But finally compared with volt controlled sounds of the first sinthis or a simple midi sound card the vst sounds are fantastic!