But that's circular. Other civilizations conquered the world, and yet, other civilizations did not produce the industrial revolution.
At its most constructive, the progressive British response has been to half-heartedly define post-imperial values as being about tolerance and inclusion
I find this to be a very interesting line of thought, though.
On the one hand, these values are merely the expression of the dominant cultural/ideological mode of the day: progressive-idealism, or democratic-liberalism, or whatever you want to call it.
In the contemporary era, they're not uniquely British. They're shared by basically all members of the global middle class and ruling elite.
On the other hand, they were chief planks in the ideology of the uber-British Whigs and Nonconformists. This tradition has been transmitted via America to the whole world by virtue of the fact that America won all of its battles in the 20th Century--in particular, WWII and the Cold War--and the fact that these traditions define the politics and philosophy of the American elite. That is, in the 20th century, Quakerism conquered the world.
Now, there are some philosophical problems with modern liberalism. I think you correctly identify one of them in that, as secondary virtues, tolerance and inclusiveness are of course noble things, but when elevated to the status of absolutes, they produce this yawning chasm of meaninglessness and nihilism that is the modern world.
In the modern way of thinking, the satisfaction of individual desires is the highest possible good. The job of the state is to remove impediments to their satisfaction, that ever more people might satisfy ever more of their individual and equally valid desires ever more efficiently. Discovering social structures that permit or amplify this is the role of social science. The process of social change in the furtherance of the liberal vision is known as "progress".
But the liberal politics of hyper-rationalism spells death for the traditional societies and communities that host it. It is no accident that all modern cultures are converging into one undifferentiated mass of grey formless goo: nothing but shopping, fucking and computer games. Such an endstate is encoded onto the very DNA of liberalism: atomisation is our inheritance.