This is a very difficult and complex question, any answer I give will necessarily be incomplete. I am also going to frame this as two different sides of a debate but this is artificial and does not actually represent an active scholarly controversy, it is just two different ways of looking at the issue.

I also want to briefly outline a way of thinking about empire that is going to be useful here: the "world systems theory" best known from the political scientist Immanuel Wallerstein. Very simply put, the way he illustrated how the geopolitical configuration of the world operated is that there are "core" areas and "periphery" areas. The "core" would be something like Britain, the "periphery" would be something like Ghana. The main way this system reproduces itself is through economic production: the periphery is defined through primary economic production (cocoa beans) while the core is defined by secondary or tertiary economic production (chocolate bars). But it has all sorts of other effects in terms of, eg, social networks (the elites in Ghana will be educated in Britain) and culture (much education in Ghana occurs in English). This is an incredibly abbreviated introduction but it is a way of thinking about "empire" that is not just one political unit assuming direct control over another political unit.

So when you think about empire in terms of cores and peripheries there is a sense in which not much has changed, the domination of Ghana by Britain was fundamentally similar to the domination of Britain by Rome. We can talk about Italy as an "imperial core" and point towards all sorts of ways that wealth and resources flowed from the imperial peripheries into it. The great building projects of Trajan, for example, were in part funded by the spoils of conquest on the Danube, the Arch of Titus has a depiction of Roman soldiers carrying a menorah because the Temple in Jerusalem was sacked and looted during the Jewish Revolt. There are other ways too such as the imperial estates in Egypt and North Africa and the biographies of people like Herodes Atticus that we can see the way that resources flowed from imperial peripheries to the imperial core, and social networks formed with Rome at the center. And of course things flowed outward as well: Roman language and material culture and fashions and education flowed into the provinces just as surely as Spanish olive oil flowed into Rome. The big difference here between ancient and recent empires is therefore about the modern world, we still live in innumerable ways with the living legacy of recent colonial empires. This is not to say that Rome’s influence is invisible, but it would also be hard to argue that Italy maintains a position of socio-economic domination of France and Turkey and Algeria.

However, there is another perspective that modern colonial empires actually were qualitatively different, the economic dynamics of global capitalism, the ideologies of scientific racism, the efficiency and extensiveness of the modern bureaucratic state thus created a form of empire that actually was new. Put very broadly, European colonial empires were able to exert much more extensive control with less need for local accommodation and much more fine grained economic exploitation than ancient empires. This is not to say that the British behaved more tyrannically in India than the Romans behaved in North Africa (the reverse is almost certainly the case) but rather that modern political and economic systems effected much deeper changes. The widely studied phenomenon of “deindustrialization” in India is a perfect example of this: the British empire in India not only did not “develop” India but even made it “less developed” in that its industrial production declined in favor of primary economic production which then fed resources into the factories of Britain. You can also look at the development of “mono-economies” in Africa, how entire national economies become dependent on a single export oriented resource (cocoa in Ghana, copper in Zambia, ground nuts in Senegal, etc).^1 This is not simply something seen by modern historians by the way: Bengali literati noted that while the officials of the East India Company were not more brutal or greedy than early elites, they were more distant, there was a visible way in which the British elite were taking wealth out of the region and bringing it to London that was not the case earlier.

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^^1 ^This ^is ^complicated ^by ^the ^way ^that ^much ^of ^what ^we ^think ^of ^as ^“colonialism” ^in ^Africa ^occurred ^after ^formal ^decolonization–the ^informal, ^de ^facto ^but ^not ^de ^jure ^relations ^of ^political ^domination ^in ^so-called ^“neocolonialism” ^is ^another ^way ^modern ^empires ^are ^“new”.

These ideas are not really in opposition and as I noted at the top, they do not represent a “debate” really within historiography. Rather they are different ways of emphasizing different things in history. There are ways in which modern, colonial empires are very different from ancient ones, but there are also ways in which ancient empires seem to be startlingly modern. In the long sordid history of human domination over other humans there are ways in which things do change the more, but also ways in which things stay the same.