The traditional patched round ball propelled by real black powder definitely has its limits, just like when you hunt with a bow and arrow, you gotta know and deal with the limits of your equipment.
Traditional muzzleloaders was all that there was before all the "muzzleloading only" seasons became popular.
The people who shot muzzleloaders were into muzzleloading first and chose to hunt with the limitations of a traditional muzzleloader during open season.
Then all the states started with the "muzzleloading only" seasons and suddenly, people bought muzzleloaders as a means to an end and the inlines shooting saboted jacketed bullets and fake gunpowder completely took over.
Go back in time to the 1970s and '80s, you entered the muzzleloading section of a large gun retailer and you saw mostly replicas of Kentucky longrifles, Missouri plains rifles, underhammers, many of them sold as kits.
Not that I begrudge the ml only seasons. The interest in traditional muzzleloaders would probably have waned anyway without Fess Parker playing Daniel Boone on the TV anymore.