This was the biggest reason for the exo/exterior rework.
The previous system was too complicated, so we created a new system to simplify it for new players.
Someone already said it, but the answer to a thing like this generally is that we don't want the UI to be too cluttered. You may feel like "more info = easier for new players", but the truth is that a barrage of data right from the start is overwhelming and makes people turn away before they even get started.
It's better to give their 34kt destroyer an indicator that speedboost increases speed by 8% and let them understand approximately what speed comes out. Knowing whether the final speed is 37.4kts or 36.72kts is largely irrelevant when you're in a match and would only serve to distract.