The training pit is obsolete and useless.
The system that tried at that time to try that Freeplayers and casual players did not have such a negative impact vs. payments, is history.
Let's simulate this, I have a 4 star champion and I want to raise it to level 40.
I put it in the pit and I see that it takes 30min to level up, wow it's fascinating, I just have to wait. After 30min I click on it and it takes another 40min to level up, it is somewhat simple and useful. But it has its Achilles heel, and that is that we must press the button every time the champion levels up. I suppose it must be one more tool to make the user stay tuned and connected.
But let's face it, who is stuck all day in a game where their gameplay is limited by energy? That is to say we to play we must let the time pass so that our energy is filled (100 of energy takes 5 hours).
So we are faced with a contradiction, we have to be connected 40min without doing anything to press a button. Now we are going to try to do the same but with a level that we need more experience and therefore take longer to level up. Suppose we go to sleep, and I put a champion that takes 3 hours to reach the next level, I am wasting 5 hours (uff for something free the truth is that I am being very stingy)
But our level 1 training pit takes 204 hours to advance a single level 1 champion to 40 without interruption.
If I read correctly, it takes 8 days ..... and that without interruptions. And it's a long time and it's fine, I accept it as a help.
But ..... today we have several bonuses to make the most of our energy, one of them is double XP (100% xp bonus), as if that were not enough we have the Battle pass (50% xp bonus) and in case We had a Raid pass (40% xp bonus). In other words, we have 290% more xp than a free to player player.
Those 204 hours we can do in 52 rounds in hard 12-3, yes, you read it right, with a fast champion we can do those 52 rounds in 5 minutes and with a slow one in 1 hour and only spending 312 of energy.
You will say hey, you are comparing with the highest, but only the double XP that is obtained weekly and at many times of the week they are obtained for free is giving you twice the advantage.
It is now evident that there are too many elements that counteract not only the usefulness of the training pit, but even its existence.
It doesn't work because there are few levels that take 8 hours, it doesn't work to improve it because it lowers the delay to 4 hours, which wastes the rest.
Or they take away the one that you have to press the button every time you level up. Or simply delete it because it is a very small grain of help that the more you invest it the less beneficial.
Do not invest in the training pit because it takes weeks for the champions to level up and you can do it in minutes and without interruptions.