There must be 30 dog breeds that are bigger than an XL bully. And double that bigger than a staff.
Great Dane
Old English sheepdog
Irish wolfhound
St Bernard
Giant poodle
Etc etc ..
Now why anyone would want an XL bully specifically.. that's another question .
I'd suggest the vast majority buying a pure breed dog ( as opposed to rehoming or rescuing ) does so for at least partially " what others will think / social appearance/ fashion " .
They'd have to , as pure breed fashionable dogs are often bred for a look , that makes the dogs life compromised health wise.
In some peoples world , a labradoodle / cockapoo is a good look. Some others a 'frenchie ' or miniature something.
For others , an XL bully gives them social status .
I'm not defending the breed or owners in any way, shape or form btw , just saying that " size " is irrelevant.. they'd always be a most aggressive/ damage potential dog breed.
If you binned every breed bigger than the police dog of choice, it'd be that .