1. It is said already, card's value is in playability or rarity.
2. I actually have to thank you for your second qustion. I understand a little more now.
The thing with ELO
or Tourney is that EVEN IF two players sit and play for same amount of time, they will not rank the same. You rank higher because you win more matches, it requires time of course, but NOT ANYONE spend that same amount of time WILL JUST WIN that many matches. You win because of skills not time spent.
The legendary cards however rewards the ones that DO SPEND TIME in completing missions but DOES NOT NESASSARILY requires skills. (Yes some, but note the point here is that even if you possess card skills you can't win these cards unless you spend that much time for missions, it's the opposite of way to win cards in ELO
I did think that the new LD cards move is to please more players on UR, given enough players being frustrated by ELO
bans and they can't do as well as before. But they do like the game and they still play a lot.
Winning Cr/rare cards in ELO
requires skill even if you spent the same amount of time.
Winning LD cards in missions requires time/grinding even if you have same level of skill.
So now I see why these LD cards being rewarded can't be super-duper.