Burgess is a joke, has have never shown anything that great, he has strength sure but thats it, he seems pretty dumb as well. He's a weaker Jack.
Plus Blackbeard is the only pirate in the crew that is worth any weight to be a Yonko.
Yeah Sabo disgraced him pretty badly and I completely agree. But he's shown great durability just like his captain though. Remember when Teach was introduced? He was a complete joke as well and Mock town saw him as a drunk idiot if anything and even G2 luffy dropped him with one punch in the impel down. And then when his true nature shows we saw how powerful he really is, like giving someone on Shanks' caliber a permanent scar the even Mihawk has never done.
It's very very hard to gauge people's level in onepiece, but I'm not gonna judge Burgess power with one fight especially when it's somebody on Sabo's level. Sabo is very strong and arguably strong as or stronger than most Yonkou's right hand man (first mate). Plus we can't really use the Jack analogy here, because Cracker is also Big moms 3 high officers and luffy was able to beat him. Doubt he would be able to do that to Jack himself in G4 tankman form.
But you get what I'm saying here though, right?