The live-service era is a tricky one to deal with, as now it feels like games aren't just after your money, but they also need your time. You have to buy the battle pass, and you have to grind for 40 hours to get Peter Griffin at the end of it.
Hearthstone is the latest big sinner when it comes to pushing players to spend more time in-game, as it recently introduced a system where the requirements to beat a weekly quest were tripled compared to what they used to be. For example, instead of having to win 5 ranked games you'd have to win 15.
The XP reward was increased for these quests, but only by 20%, which isn't really a fair deal. In a new lot of patch notes, Blizzard acknowledges that it went too far, but still the quest requirements have been doubled, instead of tripled.
Fans aren't exactly happy with this, as even with slightly less to do, they still feel like their time isn't being well-spent in the game. The maths still don't seem to work out, but this might just be the new normal for Hearthstone rewards.