I wonder if GPS makes people run faster on easy days because they would rather post an 8 mile run at 6:40 pace than an 8 mile run at 7:40 pace. There seems to be universal agreement that easy days should be easy. Frank Shorter in the recent podcast, Wejo's training advice, the elite Kenyans who run 10 minute pace at time.
Strave/GPS might encourage one type of training: tempo runs. When I was running competitively, I observed that the best runners trained at a wide variety of paces: 10 minute pace shuffles for warmups and rests between intervals, 11-12 second per 100 pace for strides, 4:00-4:30 pace for intervals, 5:00-6:00 pace for tempos, distance runs starting at 8 minutes and ending at 5 minutes with misc. bits at 10 minute pace or 6 minute pace depending on what practical joke was being played. Might not be true now.
If I were coaching, I would tell my runners not to wear watches on easy days. . . .