The Los Angeles Rams have been running training camp without the benefit of veteran quarterback Matthew Stafford practicing with his teammates. While that has certainly upticked the reps for the remaining Rams quarterbacks, at some point, the absence of Stafford throwing to his receivers is going to complicate the offense's ability to function effectively.
This is the time when teammates work on chemistry, communication, and coordination. Much of what happens on a football field is about how a unit performs together, and less about the efforts of an individual. For every great reception, there had to be a great throw.