The only shortcuts that might be worse on an alternative layout is hjkl, and you can argue that people way overuse them and it's better get into the habit of using other movement keys instead.
I've found that Vim ergonomics are way better on my own layout[0] than on qwerty, despite hjkl not being on the home-row.
Yeah, "the only shortcuts" worse are the most used ones!
And overuse argument isn't enough to even move them (it's an argument to maybe move word-based movements to the home row instead of them, but not to just move them out), let alone split them!
Your layout isn't relevant when talking about Colemak, it's trivial to make Vim way better even on qwerty since the defaults are very bad, so of course there are layouts where these letters magically appear in more ergonomic position, the argument is that it makes no sense to make it worse just to stick to the labels
The only shortcuts that might be worse on an alternative layout is hjkl, and you can argue that people way overuse them and it's better get into the habit of using other movement keys instead.
I've found that Vim ergonomics are way better on my own layout[0] than on qwerty, despite hjkl not being on the home-row.
[0]: https://www.jonashietala.se/series/t-34/