Honestly when a professional lose a match, it's not really matter since they still earn money and build their reputation.
Believe it or not, some gamblers have a reputation for losing, and they are often used in fixed fights. In these fights, you notice that these boxers come up against opponents who you expect them to win, but they end up losing because it is a fixed game and they still earn money from the loss.
Anthony Joshua's fight against Francis Ngannou was one example of a fight where people suspected that it could have been a fixed fight because of the mid-performance from Francis, who could not even fight as expected. Even though Francis lost his two fights, it made him richer.
If you bet on these fights as a gambler, and after losing, your consolation becomes that the gambler was bruised enough to your satisfaction to compensate you for the loss, I'm sorry to say, but you alone lost. The boxer you bet on who just lost will still earn some money from losing.
There are certain gamblers who are notorious for their consistent losing streaks. They are often involved in games where they have to purposely lose. During this particular match, the gamblers observed that the supposed winning boxer ended up losing, which raised suspicions of a deliberate rigging of the game. However, it is mentioned that even losing boxers can make money from their losses.
Your example was quite apt, the case of the fight between Anthony Joshua and Francis Ngannou. Many people suspect foul play in this match as well because of Francis' underwhelming performance despite losing two fights and still making a substantial amount of money.
If you wager on a fight and are relieved that the boxer you bet on loses, it actually means you lost the bet. Despite losing, the boxer still receives some money from the fight while you lose your betting amount. Thus, even though the boxer is defeated, they still gain a reward from the match.
