Depends on the distance from the toilet to a drain line. The pump (macerator) in the toilet may not be rated for the distance to the drain line. Whoever installed it may have been lazy also, and just piped it to the sump. Most Sani-flow type toilets contain a macerator pump in the unit. A regular pump would soon clog up if it had to pump solids.
If you have never made a mistake, you haven't done much.
The sump pump is located a mere 2-3' away from the tank, just picture this, the toilet resting on the tank and the sump is in the ground just a little behind the toilet which is why I question the need for the tank?