You get XP boosts super regularly. Once every 5 days you get a one-day boost, along with once a month you get a 3-day boost. On top of this, tournaments and events regularly provide one-day boosts as rewards.

You are not expected to be able to get those legendary books on events/tournaments unless you're a spender. I'm what I would consider end-game, and even I don't get those the majority of time.

It really is inefficient to farm exp without an exp boost. It'd be better to spend that time elsewhere like the dungons, or potion keeps, you can even farm the minotaur. That being said though, there are lots of ways to get exp boosts. You get one every 5 days from your weekly quests, you get some in your Daily Log-in rewards, some from Missions, Challenges, and Tourney/Event rewards. 

I suggest you check your undone challenges, missions, unclaimed rewards, etc. to see if there is an attainable exp boost that you can use while the Champion Training event is up.

Two things:

1. If you're burning a lot of energy leveling up champs, buy an XP boost with gems.

2. Watch for the weekly/monthly XP boosts and save up your energy/gems to use during those times.  In the off-times, do what Lxzy suggested and work on other parts of the game like farming dungeons.  You'll  always need more potions and better gear.  It's kind of nice having a direction on what you need to work on at any given time in my opinion.  Magic keep is open and no XP boosts? I know what I need to do.

I have the opposite problem right now, keep waiting for my boosts to run out so I can do other things besides level up champs but they keep getting extended so I keep farming XP.

Few things. Yes I know it is inefficient. That is the point iam trying to make. It is completely not worth it. And now there is an even that I cannot participate in. So that is one strike. And yes you can buy XP boosts but yeah money money money. And then you get occasional boosts yes but they seem to be instant and cant be saved up it seems. So impossible to do some decent timings on them when I have enough time to actually grind. And when I cant level food iam stuck with lower levels that prevent me from leveling when I really need it or want to.

There is no attainable exp boost for me atm. Except to buy with 140!!!!!! gems. Are they mental.

I have been enjoying this game quite some time but it is more and more looking to be a whale contest. No wonder no one is sticking longer in the game. Iam not expecing to be showered with free stuff but the value vs fun ratio is way way way off and it is getting worse.

The answer cannot be "just spend more money". 

I have some time. I dont mind spending some time while playing a game. I dont mind spending some cash while playing a game. I do mind not being able to determine my own pace and being forced to spend tons of money or else you just dont progress. I really start to understand a lot of the complaints on this forum (didnt at the start but now I see it) and really understand why there is such a small active high level player base. No one wants to be forced to keep spending hundreds of dollars per month to progress or have the patience to wait for months and months to see some progress....

1. we cant all spend 140 gems to boost. That is just wrong

2. I want to play whenever I feel. I dont want to be limited to once a week or something. Maybe I have to much time to spend or something. Or maybe this just isnt the gatcha game for me then.

I need more potions when I level up my champs. When I cannot level them up I dont need the potions :) I understand what you are trying to say. And maybe I just need to stop playing and accept my resources for that day are used.

But yeah, more and more this game is showing how few value you get for your money or your time. I mean those daily packs. Cmon who is going to spend 50dollar for 2 sacred shards and 200g gems!! Stop insulting your player base! Getting more and more convince this game in this way is not going to be long lasting for me it seems. To bad it has so much potential. But seems to be driven to catch to few players (compared to the installed copies) that spend hundreds or thousands dollars on a game like this.....I guess they almost gatcha me right...

Honestly, I hate to say "git gud", but everything you are complaining about (in every one of your posts) is something that can be solved with the tools that are available to you.

If you think this game requires you to spend money to progress, then I have a feeling this game type is simply not for you, because I expect any other game of the same type you try, you'll have the same complaints for.

If there is one thing that I agree with you on, it's their approach for handing out rewards. I agree it would be far better for *all* rewards to be delivered to the mailbox, along with an appropriate duration. Currently, that happens for many rewards, but not all - for example, daily login energy rewards get used immediately.

I will have to agree with your first line. Unless you mean that money is a tool ofcourse. This game has very high limitations (purposly, so you spend more money).

I guess we have different thoughts on what progression means. For me it means a steady rise to be come stronger and when playing more you get rewarded for it. That is not the case in this game imo.

But yeah I think you are right that this might not be the game for me. I tried. I really cannot stand bad value for money deals. I have that when buying electronics but also seem to be having that with games. 

For example ive spend 10 dollars per month playing world of warcraft but I was not limited to time or anything else. I could do whatever I wanted, whenever I wanted and got great value.

Ive spend 50 dollar on CIV5 and spend like thousand hours playing that game (and still are). Maybe it is time to buy CIV6 and get value for money there instead of this very limited and repetitive game. It was fun at the start but it seems to be getting stale quite fast.

Yeah this isn't a game where spending money has a great return on investment like other games. But that's a problem with the gacha model in general, not one specific to this game.

I personally believe the game is playable without spending any money, but I can understand why people would be frustrated at being unable to do something because of lack of resources, and being further frustrated by the high cost of getting around that through purchases.