Well, they answered your question.
You asked what is the point of improving my skills if the benefits do not continue? And you example is exactly what I interpreted.
Now, after emailing my friend, I was able to clarify a few things:
We go from work reward to ability/need reward. I can now safely say this: wages are gone. Wages will only create more inequality.
Next: At first, Trotskey agrees, should we have a soviet revolution: people will be from a capitalist society. If we continue to enforce the notion: be the best you can be for the sake of everyone (like the war effort or mass produce), then over time (the bible has a saying it will take 7 generations to forget the sins of their past, but Trotskey never specifies how long), people will care less about themselves and more for the Good of the people.
Let me explain.
John comes from a capitalist society which is now communism.
Jack was born strong. He can produce a lot. There are others in this community that are weak though. So, to be fair, we give according to need and ability which means no matter how much stronger Jack gets, he will only get the same thing (like at a job where no matter how much better you get, your boss doesn't raise your wage).
So, why should Jack get better then.
1) Jack is selfish, which is common right now, but soon Jack will learn it is no longer about him (capitalism), but if it is about everyone. The amount of lumber produced is what is important, not who did the most. What this does is put Jack on a sports team and no matter how talented Jack is above everyone else, his reward for a championship will be the same reward all the other players receive.
2) We need to think about the Good of the country.
a) war time, and you keep complaining that I should get rewarded more for making the most weapons. What you are actually doing is distracting others and if you don't be quiet, more will get distracted=less weapons=the army cannot do as well=perceived as treason. So, you will get jailed=have to spend money and time housing you in jail...all because you thought about yourself (extreme example, but Trotskey says this).
b) poor people: maybe we are producing to make more wood to make more houses for those who don't have a house yet. If Jack keeps thinking 'I shouldn't get stronger because I won't be rewarded more,' then less wood will be produced=less houses per month for people who need them
So, to eliminate this selfishness, we continue to enforce the notion: don't be selfish, think about everyone else. Be the best you can be so you be the best help for those in need. Over time, Trotskey believes that some generations forward will not be selfish at all. Without capitalism, selfishness cannot grow.
Another view: No charities. So, to be fair, Jack may have to take 10% work time off so others could work as well. They will be rewarded according to need and ability (same amount as Jack).
Both these views (points 1 and 2 + another view) illustrate a non-selfish society that works for the good of everyone while not letting people be lazy.
Now, without wages...how will people get what they need?
1) Will be fed at work accordingly. So, Jack will probably get the most food.
2) In stores now, you take what you need and public pressure will make it so you don't hoard a store. Force may come if necessary.
3) No expansion to big scale homes and businesses. That is selfish.
Now: Trotskey does allow for small businesses (i talked about those earlier), I will explain that later (You didn't ask, but I know it is an issue that will come up later).