It's a long story...

• First we had beta packs as season rewards
• Then quests were introduced with 1 pack reward per quest
• Then quest and season rewards were replaced with reward cards

So for the first few seasons, people could actually level up their teams, which was great.
But then the bots moved in and packs were going out too quick. And even though actions were taken to make it harder to bot, the pack rewards were still taken away.

It was deemed to easy to win a pack for a quest, but now some people are winning an equivalent 3-4 packs per quest. Whilst some only win 1 card.

Personally, i'd like to see a compromise of packs for season (even if it was half of what was offered before) and reward cards for quests.