I think the problem many people have with the word colonialism, besides the incredible amount of overuse and misuse, is that by the definition you provided you can label almost any international interaction as colonialism if there is even a slight imbalance by loosening the meaning of "domination". There are certainly countries that have dominated others e.g. China and Tibet but the vast majority have much more complex relationships. Take the US and Mexico, does the US dominate Mexico? They have a great deal of influence in Mexico but that doesn't seem to prevent the Mexican government or its people from acting in ways opposed to the US. They still have to negotiate treaties and enforce them imperfectly. For a strict definition of domination, this isn't it.
It helps to also attempt to imagine a total absence of colonialism. Using a strict definition of domination this isn't too difficult though it may still be unlikely to ever occur. Using a loose definition you have to assume a world in which no country has any political, social, economic or cultural advantage over another. The simplest way to do this is to imagine a world of total isolationism where no country interacts with any other. Either that or a world in which only a single nation (or perhaps only three) exists. Neither are the happiest nor most diverse outcomes one would wish for. Imagining a perfect balance seems impossible, international trade requires it, differences in population size, productivity and resource distribution enforce it. Beyond that how would you even start to prevent a difference in say cultural influence? Even among Western nations there are enormous cultural gradients. Canada has tried to mandate the distribution of its own cultural media within its borders but even that isn't enough to prevent being swamped by the sheer volume of output from the US. China has the Great Firewall and yet its citizenry still demands access to Western culture.
So for any definition of colonialism you should also provide and abide by a definition of domination.
It helps to also attempt to imagine a total absence of colonialism. Using a strict definition of domination this isn't too difficult though it may still be unlikely to ever occur. Using a loose definition you have to assume a world in which no country has any political, social, economic or cultural advantage over another. The simplest way to do this is to imagine a world of total isolationism where no country interacts with any other. Either that or a world in which only a single nation (or perhaps only three) exists. Neither are the happiest nor most diverse outcomes one would wish for. Imagining a perfect balance seems impossible, international trade requires it, differences in population size, productivity and resource distribution enforce it. Beyond that how would you even start to prevent a difference in say cultural influence? Even among Western nations there are enormous cultural gradients. Canada has tried to mandate the distribution of its own cultural media within its borders but even that isn't enough to prevent being swamped by the sheer volume of output from the US. China has the Great Firewall and yet its citizenry still demands access to Western culture.
So for any definition of colonialism you should also provide and abide by a definition of domination.