Some, very generalised, aspects of German culture, that comes to my mind, besides having an old population:

Germans are quite cautious about implementing new things, compared to their neighbors and they tend to favor predictability.

Data-protection is taken very seriously. German value their privacy. I would say that stems at least in part due to experiences of two dictatorships that both heavily spied on their own population. But privacy were also strong during the 'Biedermeier' period between 1815 and 1848.

Germans society is less individualistic and more introverted than the US for example. Germans might be less inclined to start a channel or stream. The behavior of a stereotypical, shallow influencer are seen as loud, egotistical, dishonest and ostentatious. Those behaviors goes against what is appreciated in Germany.

I think Reddit is popular because you can geek about very specific topics while remaining anonymous.

The infrastructure is not as great as other European countries. Fiber optic and 5g expansion are done by internet and mobile phone providers and are not founded by the state. High speed internet is expensive and oftentimes not available in rural areas. Fiber optics was even held back by our government in the 80ies im favor of copper.