The remnants of colonialism continue to produce winners and losers economically, with the winners stuck in local maxima where they extract value from the people, but the people themselves see only marginal benefit, and development is stuck at a snail's pace.
As with seemingly everything in life, the incentives for the different players really don't line up. Consumers lose, producers lose, and only a select few middlemen win anything at all.
The reason New York City is the biggest city in the US is because when the Erie Canal was built, the agricultural riches of the Midwest had a route to world markets. Where you have a major seaport, you also need major banks and major insurance companies to smooth out the financial needs of traders and shippers, providing the funds right away back to the farmers, instead of them waiting till the voyages were complete. (without the Erie Canal, New Orleans would have become the largest city in the US)
Yes, there is a lot of money in trading, banking, etc. At every step of the transaction pyramid, a %age is added to the price, and the %age fees charged on that go up accordingly. But that measures the true value of the product at each stage; if you have a cheaper way of getting the same product to the same stage cheaper, the (supposed) riches will be yours.
The socialist instinct ("anybody getting rich must be cheating") unfortunately obscures the real problem ("monopolists and cartels controlling supply and setting prices are the true enemies of the people") which hinders solving it; by putting capitalism in your gunsights, you make enemies out of natural allies.
It is not pleasant to think about it in these terms; but it does seem like some of the greatest improvements in general human welfare have their roots in relatively ungenerous undertakings by methodical, reasonable, self-interested actors. The Romans roads and the Pax Romana, and the profound legacy of Roman law, were not the result of a benevolent desire to help everyone in the world and save them from evil.
It has a lot to do with the unprecedented improvement in material well-being in certain parts of the world, namely the colonizer nations and a handful of successful colonized ones. The majority of former-colony states are still struggling, most with the luxuries, many with the essentials, a few with even managing a stable state.
The hard truth is the people in the developed world have only had it as good as they do because so many in the developing one have gone without to a frankly criminal degree for far too long. And they continue to be exploited. If you don't believe me look the shipbreaking yards where barefoot Bangladeshi work with plasma cutters to hack up ships beached there, or the electronic scrap heaps where people set fire to piles of e-waste to salvage the metals within, on and on. There are hundreds if not thousands of these examples where the West continues dominating the global south in clear, unmistakable ways, and precious few where the relationship goes the other way.
As someone who has written extensively on this topic, both on the internet and not, it is frankly just offensive to see this viewpoint shared as though it's serious. Colonialism benefited colonial nations, because of course it did. It wouldn't have been done if it wasn't beneficial. To the colonized it represents an entire category of scars: some on their infrastructure, some on their economies, a lot on the places in which they live, a few on their actual bodies to this day, and many simply as a gigantic, unforgettable one across their collective souls.
One way to gain an intuition for the extent of the change is to consider population sizes. India in 1600 had about a tenth of its present population. To have a population so much larger, agricultural productivity in India, as well as in the rest of the world, had to increase a great deal in the intervening years.
Another way is to consider the spread of various conveniencies of life -- refrigerators, motor bikes, microwaves, automobiles -- and affordances they enable. Relatively few people in Bangladesh own motor vehicles, but many of them find work in commercial enterprises that are only possible because of the way that commercial trucks open up the interior to world markets. Something like 12% of the world's population has cars today, and that number is steadily increasing. I am not totally certain of this figure, but I believe about two thirds of households in the world have refrigerators.
The benefits of modernization are spread very unevenly amongst the world's peoples today (and we must acknowledge that another example I offered, of the Pax Romana, conferred many advantages specifically to the Romans) but it is hard to argue that there has not been a tremendous benefit worldwide as a result of changes brought about mostly by colonial powers over the last 400 years or so. The thing to consider is not what life in Bangladesh is like, relative to life in the Denmark (or the UK, &c), but what life in Bangladesh was like 400 years ago.
The Europeans do not have it as good as they do -- and, more generally, the world is not so much better off materially -- as a result of simply transferring well-being from one place to another. There were no automobiles, refrigerators, &c, to steal from other countries 400 years. The path to modernity involved real changes in human productivity that allowed for a genuine net benefit.