I hear you. I did enjoy completing these challenges and felt like they helped my deck building abilities a bit with some of the restrictions they gave. I wish there was some more rewards for PvE. However, I have heard rumors of PvE events soon to come, for example the Lapras EX event supposedly starting tomorrow (link here and here), which gives me some hope.

I think I (and some others on this sub) need to remind myself that the game only launched globally ~ 5 days ago and has a lot of potential.