Let me explain why this shards are useles and grindy AF

First of all I want to describe my style of playing.

For example, I have 254 Deadpool and 253 Daredevil. Next reward for Deadpool is 10 command points. That's why I check him as favourite character. But during play after some tries I got Deadpool cover as usual. So, now I have to upgrade Daredevil instead, because he is next in the list. And the chance of his upgrading as favourite character is pretty high, because I spent some tries earlier. But now all collected shards for Deadpool become useless, and I have to grind them for Daredevil from the start.

Earlier I checked all covers close to rewards. And if I got some needed cover in usual way I still kept good chances to get another by "favourite" bonus. Now this shards system is usefull only if you want to upgrade only one character. If you share shards among all needed covers - you get them faster without shards. For example Ironman, Doom and Widow are close to rewards. I check all them as favourites. I got Ironman and Doom as usual and boom - Widow as a bonus! Now if I check all of them - I will get them faster and all shards I grabbed will be useless.

And I didn't mention that if you got 3* cover from ISO - you always got bonus character. Also with 10-packs. They always gave you a bonus cover if you favourite character was in the pack. There were days when I got 2-3 bonus covers. Now I haven't seen any bonus from the start of these f..g shards.