GAIA stats are almost useless

Why are Gaia stats so wrong? 

1)If one does a loop hike, the ascent and descent figures should be close (allowing for +/- GPS 20 foot accuracy) but are often off by hundreds of feet on a substantial hike. 

2)The MAX and MIN figures very closely match topo maps, but a difference of 1272 feet is reported as an ascent of 759 feet on an out and back hike.  The track is complete so it is not the phone was off for a portion of the hike.