There are some valid reasons to use software in English as a German speaker. Main among those is probably translations.

If you can speak English, you might be better of using the software in English, as having to deal with the English language can often be less of hassle, than having to deal with inconsistent, weird, or outright wrong translations.

Even high quality translations might run into issues, where the same thing is translated once as "A" and then as "B" in another context. Or run into issues where there is an English technical term being used, that has no prefect equivalent in German (i.e. a translation does exist, but is not a well-known, clearly defined technical term). More often than not though, translations are anything but high quality. Even in expensive products from big international companies.

UX translations are broken most of the time for most of the software and not just in German. People just pretend it's working and okay, when it's not.

And then developers just do N > 1 ? "things" : "thing" without thinking twice, not use pgettext and all the other things.