Economic transformation is accomplished by human thought and will. Capitalism is a human made system, based on the physical and evolutionary laws of nature. Capitalism can not die a natural death, as Marx opined, because it is a human-made social system. Consequently, all great historical transformations are the cultural product of preference changes in human values; digitization will add exponential speed to these social processes.
Capitalism transformation is not necessary. Some countries just started the free market, others are the best in competition and accumulating wealth, others have large monopolies and exploit citizens. In spite of that, capitalism is changing, developing and thriving. If the transformation will be necessary, it won't be because of inequalities or accumulated and non-used money but other reasons.
It looks like the highest peak of digital disruption is over. Autonomous machinery and robots will bring the new era. Maybe this will make the transformation of capitalism necessary.