Nope.
Consider that Chad, Jonathan, Pete and many others in the world all spend a huge chunk of time inside on trainers. Then recognize that they all know how to sprint well, despite that trainer time.
Sure, Nate needs to work on his sprint. But do you say the same for the other examples?
No, because they all spent time to learn how to sprint, outside, and can reproduce that anytime they want now that it’s well learned. Nate is doing the right thing by working on his sprint outside. Using help from other experienced riders, along with the video review, are super handy and will hopefully lead to him becoming a better sprinter with more correct technique.
This example shows that sprinting is something that needs work and the amount of work will vary from rider to rider. It’s impacted by prior experience and the amount of time they spend on learning and perfecting the skill.
This is not about trainers, it’s about learning and applying a proper technique. This is best accomplished outside and under the guidance of experienced riders to help the process.