When does Trunks grow up?

Are Goten and Trunks then
ever in DBS as adults
to be shown?
The film will finally be out next month Dragon Ball Super - Broly Out. A lot has already been said about this film in advance and we can be curious to see what will happen in it.
Unfortunately, Goten and Trunks still look like children in this film, even though they are young. That had happened at the latest in Universe survival-Arc in the series Dragon Ball Super made noticeable because it takes place four years before the 28th Big Tournament and consequently in the year that in the alternate future Future Gohan was killed by the cyborgs. Future Trunks was 14 years old and already matured. But the "normal Trunks" is 14 years old and still looks like a child.
Son Goten is only one year younger and therefore it is also sad that he is also not yet in Dragon Ball Super has aged.

Son Goten & Trunks in DBS - Broly
vs.
Son Goten and Trunks at the end ofDBZ
Let's be honest: who can deny this inconsistency? After all, it would not fit so well with the 28th big tournament, where Son Goten and Trunks grew up. That would turn out to be a disastrous plot regarding the whole Dragon ball-storyline flow.

In any case, I have put forward a theory that is so far coherent. Because so far neither Akira Toriyama nor his assistant Toyotarō have commented on it.

I don't want to chatter any more, so let's start:

Future Trunks at age 14
vs.
Trunks at age 14
First of all, you have to keep in mind that the alternative future is dystopian and consequently Future Trunks trained hard with Future Gohan. Future Trunks had to grow faster, so to speak.
The normal time level is more peaceful and Goten and Trunks can fight, but they didn't train really hard (regardless of the fact that Vegeta once took Trunks really hard during training).
In other words, certain circumstances or lifestyles can accelerate the process of puberty.

The aging of Coby One piece.
Apparently his training has that
Accelerates aging process.
We are also familiar with the same phenomenon One piecewhere Coby - who was 16 years old when he made his debut appearance but looked like a kid - joins the Navy; looks more grown-up after lengthy training and has aged even more after the two-year timeskip. If I remember correctly, Future Trunks probably went through a similar development through hard training as Coby.
And as already mentioned, the Trunks from the "normal" time level - unlike its counterpart from the alternative future - did not go through such a training.

The reason why Son Goku was first
from the 23rd big tournament as
Adult appeared.
Here's a little digression: the deadly argument that Son Goku in Dragon Ball Classicalso still looked like a child is of no use, because this is a question that cannot be answered on the action level, but only on the meta level (see the picture on the right).

Furthermore, Son Gohan is during the Cell-Arcs initially aged normally and then trained for a day with his father Son Goku in the space of spirit and time; as is well known, one day corresponds to one year.
Son Goten and Truns, on the other hand, did not train in this room for too long. As a result, they did not show any signs of aging.

And by the way, the different aging of Son Gohan, Son Goten and Trunks has nothing to do with the fact that they are human / Saiyajin hybrids. So you can't say something like, "Gohan's Saiyan DNA was dominant; therefore, he has aged faster than Goten, whose dominant DNA was that of humans."

Conclusion:That Goten and Trunks in Dragon Ball Super still look like children, even though they are already in their teens, could be related to the fact that they did not go through any hard training and consequently could not mature any faster. Especially Trunks, who didn't have to live under the same circumstances as his counterpart from the alternate future.
But presumably summer 2019 there should be new episodes of the series Dragon Ball Super give that chronologically after the plot of the upcoming movie Dragon Ball Super - Broly are located. Let's hope that Son Goten and Trunks will finally age and also play a bigger and more decisive role in the further course of the plot. Who knows? Maybe then we will finally see the grown-up Gotenks.
It would also be cool if Son Goten and his father were in DBS regularly
would train and not very shortly like immediately before the 28th big tournament
At the end of DBZ.
Now I would be interested: How about you guys? Do you agree with this theory? Or do you have another plausible explanation ready? Feel free to write it in the comments.

PS: Here you can find other theories that I have already written. If you haven't read it yet, please check it out as well: