Yes that could be why its depicted that way. However I can't imagine that's anything close to what the real performance is. For instance if you watch the NG APG-81 video on YT, you can see it quickly detect and track multiple targets beyond the circa ± 22°long range scan volume (yes I measured it.), some out to 40° out to near max range of the display (80nm.) Compared to the F-35's tactical situation display, it displays what I believe is the radar scan volume with green colored elongated shapes, interestingly with a small area in the middle with no coverage:

Now from what appears to be an early slide about LM JAST presentation, shows the long range volume as ± 40°. In this case the long range volume is slewed left with the (much) reduced range volume visible on the right side of the TSD and A-A formats.

Perhaps what is represented on the F-22 are simply notional non-representative displays and what we see now in this JAST and F-35 is more representative.