So tbf i only learned about Grant in Christian Fundamentalist Baptist school, and likely my teaching was not great...but what i learned is that he basically just threw superior numbers at the opposing army not caring how many men he lost, and this is the only reason he won
To be fair to the the slim margin of truth there, he did take somewhat higher losses but also kept campaigning so those losses were in service to a military goal. Previous generals would take fewer losses but immediately retreat back north, allowing the CSA to recuperate from any damage.
But Grant wasn't the only guy to take high losses. Lee threw away a lot of good men at Gettysburg for absolutely zero gain, even if you set aside Pickett's Charge. It was a battle that was not nearly as close run as people claim and the overall campaign was boondoggle.