I didn't say it was meaningless. I said it was rambling. It is badly written and kind of all over the place. The actual meaning is clear enough - he makes his points.
The word 'rambling' quickly spread around the Democratic controlled corporate mainstream media. The latter, fully commenting on the letter, never actually revealed its full content.
This is an example of present day propaganda, where many people let the media think for them.
But there is a shift now in the US, as more and more people start doubting the veracity of the so-called news, resulting in millions of people switching off mainstream media.
That explains why the Food Channel has a higher viewer rating than CNN.
The backlash is growing, with the result that, despite his failings, Trump's approval ratings are actually increasing, and he is now projected to win the next elections.
This 'rambling' letter, not written by Trump, is a point-by-point rebuttal of the Democratic Party controlled House of Representatives politically motivated impeachment trial, and is clearly meant as a historical record.
Call it what you want, the 'rambling' letter will stand in history as a rebuke to the Democrat controlled House of Representatives of the 116th US Congress.