And that is where the fallacy lies, Bernhard.
One cannot say that Energy does not get lost (and indeed all scientists are saying that) and requiring Energy to come into being at the same time. We have data for the first; we have no data for the second. So we better stick to what we know.
The facts speak for themselves:
The transition of (some) Energy into matter took place some 13.8 billion years ago.
This can be put in a very simple equation:
1 + x = 1
With 1, the total amount of Energy is pronounced. We have no idea of course how much that is, but we do know that the total will always be the total, and so we can use 1 to represent that total.
The x in this equation is the transformation, though the = sign is the spot where the transformation is actually happening.
The x is of course 0.
1 + 0 = 1
Yet this zero must not be thrown out with the bathwater. The zero needs to be understood as fundamental change.
If we take a married couple and they get a divorce, then the divorce is that zero. It did not kill the folks, just their married status and connection. Fundamental, however, it is. They are no longer married.
If we create money, then the zero occurs for the person opening up their wallet and seeing there is nothing in there. Fundamental it is because that person has nothing to spend and will need to find ways to get money. A pull is placed on that person.
The zero is a fundamental separation of some important kind.
So, we have a prior state in which something happened that led to the establishment of a separation in that state. In plain words: the prior state got torn up in the way it existed. And it did so by itself.
Allow me to provide some more analogies to answer your question. They are often easier to understand than scientific language.
If we wind up a toy to the point the winding mechanism breaks, then we can sometimes still play with the toy, but it won't do its magical trick anymore.
Same with the prior state. We may never understand what the magic was that got lost, but the current state lost a specific ability that once existed among all energy.
That should answer your question. Energy that is not of matter will indeed have Energy to establish what you call work. It will, however, be work that existed for real in that prior reality. When there is not yet any matter, then it makes no sense to express that work in a material sense; it must be expressed in the pure energized sense.
We can actually still see some of the magic.
At the subatomic level, we have two kinds of linear matter (neutrons and protons) and we have one kind of non-linear matter (electrons). Combined, they are matter.
The electron is pulled into the linear reality because of the positive charge of the proton. The electron fully neutralizes the charge, so the universe is a neutrally charged place. At the subatomic level, however, that charge is not overcome, so we have a charged QM level while the big picture is neutral.
That's it, Bernhard. If you see this, then you can see that we are indeed existing in a strange twilight zone of two different kinds of energy combining, meanwhile both from the same origin (that we don't know all that much about).
As far as I see it, we cannot have all prior Energy transform 100% into matter because that would exists for 15 minutes tops and then revert back into the original format. It would be illogical to have all remain all and then all remaining something else. So, we have to have a separation already between what is remaining of the Energy in its original state (which is probably quite a lot of Energy that we simply cannot observe) and that what got transformed into linear matter sprinkled up with some original Energy inserted in that linear reality. The separation is then between us and the remaining invisible Energy while the separation is also instilled within ourselves and our very own matter.
Curious how you will respond to this. Will you accept that Energy does not get lost, or will you accept that once there is matter, then fully everything had to have come into being at the same moment?