Does range of motion really matter?

Short answer is “yes”.

Range Of Motion (ROM) absolutely does matter, it doesn’t always have to be “full”, is goal specific, and dependent on the individual.

Some pros of larger ROM:
More muscles being used.
More total tonnage moved.
More movement variability.

Some cons of larger ROM:
Greater room for error.
Higher technique requirement.
Limits usable load.

Some pros of smaller ROM:
Targeted to single muscle group.
More load availability.
Less room for error.

Some cons of smaller ROM:
Less muscles being used.
Less total tonnage moved.
Less movement variability.

There are pros and cons to larger and smaller ROM’s and they’re goal dependent.

Most people however, will benefit from the middle ground of these markers.

Larger than smaller ROM, excellently controlled technique, using a moderate load, applied across a handful of movements....
FOR A CONSISTENT PERIOD OF TIME AND EFFORT....

TL;DR - ROM matters but not as much as frequent consistent effort.