I want to highlight that maybe today, big conglomerates are rare, but this is also because during the late-20th century, the trend was to break up conglomerates to increase competitiveness and improve financial performance of companies by focusing on the best businesses. If you look at the situation before that moment, Japan's situation would still be on the extreme side when compared to the other developed nations at the time, but not as unique I think.

In retrospect, I tend to think that this take was naive. It probably increased financial performance but it discouraged taking risks, and pushed the multidisciplinary skills out of companies in a way that is hard to reverse, inducing knowhow loss and probably slowed down innovation. But this is only my personal analysis and I am no economist.