Management is correct, if that's the question.
In some very rare bleeding edge cases it is true. Everyone wants to think their company is working on those areas. But here's the truth: your company (for any "you") is actually not.
If you're writing code that is inventing new techniques and pushing the hardware to limits not before imagined (say, like John Carmack) then yes, a single superstar is going to outperform a hundred juniors who simply won't be able to do it, ever.
Asymptotically close to 100% of software jobs are not like that (unfortunately). They're just applying common patterns and libraries to run of the mill product needs. A superstar can outperform maybe 3-4 juniors but that's about it. The jobs isn't that hard and there are only so many hours in a day.
This is made worse today because neither quality nor performance matter anymore (which is depressing, but true). It used to be the software had to work fast enough on normal hardware and if it had bugs it meant shipping new media to all customers which was expensive. So quality and performance mattered. Today companies test everything in production and are continuously pushing updates and performance doesn't matter because you just spin up 50 more instances in AWS if one won't do (let the CFO worry about the AWS bill).