The advised rate of filtration is at least 4 times your aquarium's water per hour (depends on stocking levels and whether aquarium is planted). Hang On Back (HOB) filters can't do this on a 75g, they are designed more for smaller setups, particularly where reduced flow is important, for a Betta fish for example.
The bigger the tank gets, the bigger an internal filter would need to be and so it ends up being counter productive, as they take up your tanks valuable space. So cannister filters are the more heavy duty filter required for the bigger tanks, that can perform the 1000+ litre / hour turnover