The line between professional and amateur porn is often a thin one.
By professional I simply mean that the real objective is to make money. Being a sex worker and setting up a business around sex.
If by "professional" you mean only working for a production company with actors, I can tell you that there are many girls who don't fit that definition but do professional porn. OnlyFans has "democratized" professional porn.
In fact, many camwhores in OF sell themselves as amateurs, but in reality they are professionals, who have even registered their business as a proper company, pay taxes and everything related to an audiovisual business.
For example, Jack (of Jack&Jill) is clearly a professional. In fact more so than many other actors who work for Brazzers for example, and he certainly makes more money than they do without working for a production company. He is his own boss.
And the same applies to Reya Sunshine, MissLexa and many other camwhores.
In these cases it is very clear that they are professionals because they even have deals with actors to produce content to sell. They don't just fuck their partners, they actually look for actors to produce better material.