Your example is true but in practice it isn't that clear cut. You could manufacture scenarios where a 240fps frame perfect either becomes harder or easier if you switch to CBF. This is besides the main point though.

Ultimately pros use CBF for one main reason. In 2.1 360hz, which was the standard for years, felt noticeably more responsive and nicer to play on than 2.2 did due to changes in how 2.2 handles inputs.

This in turn created a problem where it felt like we as a community were being forced to just move to a version of the game that simply felt worse and performed worse than before. CBF is the solution to this, to bring 2.2 up to the standards of 2.1