Regular gambler = has long-term losses
Professional Gambler = has long-term losses
In both cases there is no big difference, so much so that the guys who consider themselves sports bettors keep creating YouTube and Telegram channels and selling courses as a source of income and do not show proof that they are making constant profits from gambling. In my opinion, people should not gamble with the intention of making long-term profits because they will fail. I've seen many sports bettors who consider themselves professional bettors but who never post their supposed profits
In economics it's said that the end justifies the means and since professional gamblers and regular gamblers both faces the same fate on the long run, I don't see much difference in both. Professional gamblers and regular gamblers needs luck to win, a professional gambler can make all the perfect analysis but not win meanwhile a regular gamblers can bet on instinct and win big. People should not see gambling as a business except for the casino owners, because it's not easy for gamblers to beat the casinos on the long run. I prefer to be a regular responsible gambler, nothing too serious, use amounts that I can afford to loose to try my luck.
I see a difference between professional and regular gamblers but you may not find much difference between them. There is a difference in their losses from gambling such as professional gamblers are less likely to lose and they decide their strategy according to their experience in casinos or betting and even if they do not win most of the time, they win less. Among regular gamblers you will see the possibility of addiction and their losses are much higher than experienced ones. Casual gamblers do not get the time or opportunity to analyze beforehand so they continue to gamble on average relying only on luck. Experienced gamblers are ahead in analysis but gambling is never based on perfect analysis because luck is a big factor in your loss or win.