They  are  called  advanced  quests  for  a  reason.  They  should  be  more  difficult  to  complete  than  daily  quests.

Advanced tasks are also doable as long as you are a while in game. I'm in game for 200 days so I know what I'm doing. 

This is only because the Arena is still so broken that makes the battles very hard to win and progress.

I guess I will just drop my tier by dropping defense team to get easier wins now. Too much time consuming on Arena every day.

In all honesty, I'd say they should just remove this one completely, although your suggestion of lowering the material count may suffice. All other advanced quests can be completed almost irrespective of your current progression level (though I suppose the 8M dmg to CB may be tough for some people).

That quest could be 30 wins required if you're unlucky. It's both risky and time consuming. Another quests to consider changing is the one to beat a team in the arena with higher power (Plarium: "power doesn't matter", also Plarium: "power matters a lot") since it just screws over people who don't go hardcore speed team, as if that needed any additional encouragment.

I'm not particularly fond of the beat-a-FW-boss one either, nor the ones to play a classic/tag arena match with a specific affinity or faction. At least the latter ones can be done by just throwing away a token at worst, but how far do you have to be for the average person to be able to put together a reasonable team using only a single faction or affinity combination?

Beating FW boss may sounds tough for early players but it becomes easy with time. As it doesn't require you to beat high level boss.

I'm at day 199 and I still have 2 factions that I haven't pass the first boss. But that's okay since everyday you get at least two FW ongoing so the chance that I meet the 'beat FW boss' task + unlucky to have both factions on same day are pretty slim. 

while you are at it, among the CB daily advanced chores is one to go 8 mill with the CB. That is pretty tough cuz I think it is the only CB task that has to be done using just one key.

Are you sure it needs to be with one key? I can't validate this as I do well over that amount regularly, but it would be strange if that were the case.

beating CB with 8M shouldn't be difficult to achieve. You can do it with multiple keys for sure and you can do at least 3 keys per day (4 keys in total a day). You don't need high end champions, you just need the right one + some knowledge about CB (plenty of videos on Youtube).

I beated Brutual CB (21.7M) stably with two keys with my all rear champions team: Frozen Banshee, Kael, Conffin Smasher, Warmadien and Apothecary. Then I slowly moved to higher tier chamipons but Appothecary and Frozen Banshee are still in my current CB team. F2P here.

Only ONE KEY is allowed for the 8 million.  Stop thinking everyone else is just like you and has what you have. 

Even if it were only one key, as far as I remember, you aren't restricted on difficulty. If you're unable to do 8M damage with one key even on easy, then you likely can't complete many of the other advanced quests either.

I am where I am, if I am working Easy then that's what I am doing.  Right now 8M on Easy is tough on one key. No I cannot do all the advanced quests but I do not have to, it just takes me longer. Fortunately 8M is not every day.

Take your mightier than thou attitude and shove it.

Once again, you can be spiteful and bitter if you choose, but accomplishing more than 8M damage on easy with one key should be effortless regardless of your current progression.

If you're unable to get that level of damage, I highly recommend you create a new thread with your champions, as you are losing out on important progression pieces by not advancing in CB.