During seven years of blogging, I have been writing thousands of articles in German and probably a couple of hundred mostly shorter posts in English.
Comparing writing in German and English, it amazes me how much more energy is required to draft a proper text in German. Whenever I have a specific thought or observation that I think about putting into words, it feels to me as if doing it in German is much more exhausting.
Now one reason might be that not being a native English speaker, my perceived easiness of blogging in English is caused by my choice of an overall less sophisticated style, simply due to a lack of vocabulary and experience. But honestly I do not use a very advanced German either, rather a pragmatic one.
My guess is that the complex German grammar, the vast amount of interchangeable German words meaning similar things with only slight but potentially important nuances as well as the pressure within the German cultural sphere and society to show intellectual capacity through a completely flawless, perfect language is what turns German for writers into quite a battery drainer.
Before some feel urged to tell me why German is so much better than English: There are probably a thousand advantages and reasons. But if you only look at the goal of describing facts, context or thoughts in a couple of sentences and doing that with as little mental effort as possible, then I believe English is the superiour language.