The pen is only a little slower than the line pen. As for whether it is slow or not, it depends on your level and needs, but it is not completely stopped, nor is it repeated painting. Novices are not familiar with using the pen, and the control with the pen is unstable. You need to use the pen a little slower, while the master is relatively faster, so you may not even see the change of speed. The same pen, the pen pressed repeatedly is obviously slower than the horizontal pen, and so on. These are all differences in speed.
Another element of brushwork is strength. Pen handling usually needs to be coordinated with pen lifting, which is also a sudden action that is not at all, but a powerful process and a natural transition.
It is necessary for writing and hard writing. If there is no pen, either the stable font leads to slow writing or the fast writing leads to unstable font. If you want to write fast and well, you must write fast in fast places, such as pens and hairsprings, and slow in slow places, such as turning points.