I think the simple view is wealth is zero sum. I have a pie and there’s only eight pieces. If I have seven pieces then you can only have one. Easy enough to split the pie and we both have equal amounts. But it’s not possible for you to have more pie without me having less.
In the real world it is possible to create value. And the things human value are intangible. So if you paint pictures and I sing songs, you paint 5 pictures, I sing you five songs we are both happier and have more value. I can’t paint so I value a painting at 100 whuffie. You can’t sing so you value songs at 100 whuffie.
In economics they can this guns and butter and use it as an example of trade increasing wealth.
If country X is really good at making guns but marginal at making butter and country Y is really good at making butter but marginal at guns they have to allocate labor to make both since everyone needs guns and butter. So each country makes $100 worth of goods at the total value of $200. However if country X only made guns and Y only made butter they could exert the same labor but have $400 in total value. Neither country is worse off.
This works in part because money is imaginary to reflect how people value things.
This works more with no tangible things that can be reproduced so it’s quite possible for someone to make a trillion dollars worth of software without taking a trillion dollars away from somewhere.
[0] https://www.khanacademy.org/economics-finance-domain/microec...