Similar experience as you the last year or so.
I do think a bump in frequency would be welcome. As you noted, they are standing room only and often a significant portion of riders are airport employees. I wonder if the Q70 may be losing riders with luggage because it is not easy to navigate the sharp twists and turns of a NYC bus while standing with your luggage for the uninitiated*.

*Level 1 is the Q70, level 2 is the NJT 62 from EWR