I think that’s a pretty good brief definition, with the caveat that CRT is very complex and not monolithic – there’s plenty of debate within CRT advocates about what it means and what we should do about it.
My definition, briefly – CRT posits that race is socially constructed, with no significant biological basis; that, over the centuries, race has been socially constructed as a tool to aid the powerful (who are usually white males); that this has been used very successfully to divide, conquer, and aid in other aims of the wealthy and powerful, to the point that racism in some form has infiltrated deeply into most government and societal institutions of the United States; and that it’s this institutional racism/bias/bigotry/etc., rather than the personal actions of those individuals motivated by personal racial animus, that is responsible for most of the harm of racism in the US. I’m much less informed about CRT (and the facts of race and racism) in other parts of the world, so I’ll limit my comments to the US.
It’s hard to conclusively prove all of these things aside from that race (and therefore racism) are socially constructed. But IMO it’s the best explanation of so many facts of the world and society around me – both provable, citable facts (i.e. statistics and the like) and my personal experience. It explains why, both statistically and in my personal experience, black people are faced with so many more and greater challenges in achieving success in most (but not all) areas of life. That’s why I see it as a useful theory. And unless/until something more useful and more explanatory comes around, I think it’s the best explanation of the facts of race and racism in America.