If there’s a ton of low hanging fruit to be picked and large developments possible just by sheer brute force, you can achieve quite remarkable effects. These brute force economic developments were effective, but not efficient.

A huge issue for the Soviets was the immense coverups of failures and underachievements. The plan demands a factory make 10,000 widgets per year. Failure is not an option, because you might get thrown into gulag as a saboteur. So they sacrifice quality or outright lie to meet the quota. If you get that all over the system, you end up with bad data and thus bad decisions.