It depends on what you are looking for.
Professional tutors have more training, in my case it was more than a TEFL certificate. I have been teaching for 7 years. I have seen some good community tutors and you can see that they can even be better than some professional teachers.
You have to check their profile quite well.
I have seen overpriced professional teachers here. I mean if you want to improve just on conversation, getting a community tutor is a cheaper option.
I would agree with @Davi Sales in terms of reliability of Professional teachers. This is our job. We do this for a living so we treat every class like a business appointment. Like for me, even if there is a blackout in my city or no Internet, I have prepared the laptop powerbank and Internet backups because this is a job for me and students rarely have the time to reschedule. Being in this business for 7 years, I know the ins and outs of this business. Professional teachers have a lesson plan at least and it is customized. Every class, I have a pdf file sent to my students, it includes grammar corrections, paraphrasing, YouTube video recommendations additional materials that is why students comeback. I agree with @Phil that there are great community tutors but it also depends on your experience.
I had an Italian student who took classes from community tutors who are still studying in the university or just backpacking. The quality of class is not that good because it is not a job for them. It is just a hobby like what @Phil said. A person who treats a class as a job and a hobby has a different approach.
It's just a temporary means of earning extra income. As a result, the class quality is substandard which should not be.
The experience is different for each person of course.
There are pros and cons. You have to take into consideration your budget, your goals and what you really want.
You have to try in order to know. There are professional teachers with reasonable prices. There are community teachers who can even be better than the professional one's.
For exam preparation though, I suggest getting professional teachers.