Economic planning leads to faster economic growth in developing countries and increased general welfare in developed countries
Recessions, depressions, and crashes are an inherent part of market capitalism. This means that during these depressions, productive forces go unused and production sharply decreases. Planned economies can deliver consistent economic growth, and have done.
Information technology and increased computational power allows for the collection of information on a mass scale, as well as the ability to compute an economic plan in a short period of time, automatically.
In capitalism, if someone fancies themselves good at planning, they can start a business and we'll see. in socialism, which is what you probably mean by economic planning, they just have to grab the government.
Unemployment is an inherent part of capitalism. Full employment is at best only temporary, meaning that market capitalist economies are always Pareto inefficient. Socialist planned economies can guarantee work for all, meaning that all available labour is utilised.
Replace "unemployment" with "bad things" and "work for all" with "good things" and the sentence still makes as much sense. Or replace "capitalism" with "system I don't like" and socialist planned economies" with "system i like"