Speech is an action, just like any other. Like other actions, it is expressive, context-dependent, subject to interpretation, it is a physical phenomenon, that has physical effects on its listeners. It was also shown by Brison[0], Schauer[1] and others that the consequences of speech, in particular ones of harm, can be remarkably similar metaphysically and in gravity.
Whether or not the German government's regulations are good ones, the conclusion that a government should have no right to regulate speech (just as it regulates other actions) seems to be on shaky ground.
[0] https://www.cambridge.org/core/journals/legal-theory/article...
[1] https://www.jstor.org/stable/2381631?seq=1#metadata_info_tab...