In the case of everyone making the same salary, you could certainly still sabotage someone's success but I don't see how having the same salary makes this type of mentality _more_ likely than at a company with a more typical salary distribution.
My concern with everyone having the same salaries is that, potentially, employees have less motivation to excel in their individual work and are more likely to do the minimum to just stay in good standing with their employer and not get fired. Maybe a company can offset the lack of direct financial motivation with more of a team motivation that the financial success of the company as a whole results in financial reward for the individual or some other way of recognizing individual success inside the company.
I am doubtful this flat salary structure will result in a more successful company overall but I do think it's good to try new things. And yes this has probably been tried a number of times before but maybe not exactly like this. Or maybe some other external variables have changed w.r.t. other attempts in the past and this time it works. The typical salary structures we see in US companies today are the result of a large number of trials and errors and learning.
I totally understand why companies want to pay less though. It's massive cost savings and it makes sense for them to hire for less money.
