This is a very common sentiment I’ve seen from boxers and boxing fans they have a superiority complex over other combat athletes. Even in their own sport a boxer can lose or struggle against another combat athlete.
A lot of Thai boxers have a Muay Thai or kickboxing background before switching to pro boxing. Especially in the 70’s and 80’s some of the best Muay Thai fighters had some great success in pro boxing.
If it's not at an all-time low, then it's not too far off it. Boxing is steeped in history, and the cultural importance creates an air of arrogance amongst a large portion of the fanbase, that's my theory. I am guilty of it myself. Ali is arguably the most well-known sportsperson of all time, but even the likes of Louis-Schmeling had gargantuan cultural significance against the backdrop of WW2 on the horizon. Not to mention pioneers like Jack Johnson, another hugely significant sports figure who reshaped American culture. Even Mike Tyson's rise was a phenomenon and catapulted the sport back to relevance. For so long, it was the only true global combat sport, highly accessible, and steeped in rich cultural significance. 25% of the world's population watched The Rumble In The Jungle. Ultimately, though, a combination of ridiculous PPV models, the best avoiding the best in their prime, and other combat sports emerging as competition throughout the late 20th century and early 21st century, like MMA, has saturated the market. It has also completely dispelled the myth that the world heavyweight champion is the most coveted prize in sports or is the baddest man on the planet. It has also suffered from the lack of a true box-office star with crossover pizzazz. Conor McGregor in boxing throughout the 2010s would've been electric, for instance. Mayweather was great but he was boring for casuals, had zero charisma, and was the face of the sport, not to mention he ushered in the idea of boxers being strategic businessman rather than Gladiators who went to battle, these things matter. Usyk vs Rico and Ngannou vs Fury have been the cherries on the cake in many respects. It's hard to maintain box-office appeal and an air of invincibility when you're basically the best in a niche. Professional boxers would get eviscerated by pro cage fighters and elite kickboxers in the kickboxing arena. As much as I don't like MMA or kickboxing and don't watch it, it is a bitter pill to swallow. The only way for it to remain relevant would be if every crossover boxing event ended like Joshua vs Ngannou. When fighters from other disciplines move to boxing, play by boxing rules, and give champions gruelling fights for 10/11 rounds, this continues to rip through the little prestige boxing has left. So does Jake Paul moving from YouTube to fight a 2x champion and Olympic gold medallist. 30 years ago, the idea of a public figure fighting Mike Tyson would never have been contemplated, but boxing has fallen so far that this is where we are at now. So yes, the sport is not considered serious by many people, which is absurd for something so dangerous, but many of these problems have been created by people within the sport, not outside it.
Welterweight and middleweight have been basically wastelands compared to previous eras for a long time now. Boxing goes in cycles but those divisions are usually the most prestigious alongside heavyweight.
Americans have made a mockery of what was going to be the biggest card in Australian boxing history. Spence changes weight Charlo doesn't make the flight Fulton changes weight and misses it by 6.5 pounds. Weak. The sport of boxing is at an all time low.
Yes, it is utter trash. Shot barrel of lard Fury and Glass Jaw Joshua both fighting binmen in backwaters is testament to that. All to build up to a fight that is a decade too late because they are scared of each other. Also, there are too many promotors and governing bodies. Finally, although Glass Jaws exist in boxing, in recent years there have been few remarkable episodes of Shattered Glass, largely due to fighters avoiding each other to protect their Chin.