If you regularly get paid to do something, it is your job.
Maybe you are good at your job. Maybe you are not. Maybe some people think you are and others think you aren't.
If you do something without getting paid to do it, it is likely a hobby.
Maybe you are good at your hobby. Maybe you are not. Maybe some people think you are and others think you aren't.
I get paid to create, update, and maintain software. That is my job. If I'm doing my job poorly, that does not make me a "hobbyist". It makes me someone who does his job poorly.
One of my hobbies is playing guitar. And no matter how good I get at playing, until the day someone pays me to play the guitar, I'm still a hobbyist.
There are many hobbyist guitarists whose musical skill level is equal to or greater than the skill level of professional guitarists. And while you may sometimes hear a talented hobbyist guitarist lament that some untalented guitarist became wealthy playing simple songs, it would never make sense to anyone to claim that the 3 chord playing rock star could or should be denigrated by labeling him a "hobbyist".