It's not that deliberate practice isn't a big factor and very important. It's the idea that it's massively and overwhelmingly decisive.
For example, this meta-analysis of sports performance found that deliberate practice was important but not overwhelmingly so, accounting of 18% of performance on average.
It seems like there is a lot of plasticity in human performance, and it may be the case that many of us can get pretty good at a lot of things, but there also appear to be many factors distinct from practice that make substantial contributions to performance.
For example, this meta-analysis of sports performance found that deliberate practice was important but not overwhelmingly so, accounting of 18% of performance on average.
It seems like there is a lot of plasticity in human performance, and it may be the case that many of us can get pretty good at a lot of things, but there also appear to be many factors distinct from practice that make substantial contributions to performance.
https://journals.sagepub.com/doi/abs/10.1177/174569161663559...