I suppose the usefulness of the language depends partly on where you live and what your career plans are. I took German through high school and took several courses in it in college. I greatly enjoyed learning what I learned. However, I became a social worker in the United States. Unfortunately, there has never been an occasion when I was able to use it, other than hearing a few lines of it in a few movies. I have not used my German in over 35 years.
Here in the U.S. we have many more Spanish speakers, we have Spanish television stations and Spanish radio stations I can listen to, and Latin American countries are much less expensive for travel.
Both German and Spanish have many, many words that are the same as English, but also have a lot of grammatical differences. I do not think one language is superior to the other, I think everyone just has to decide what opportunities they may have to use different languages. Recently I started learning Spanish. Someday I might get back to learning German, but all the facts above do not change my mind that Spanish would have been a much more useful language for me to learn when I was young.
I guess that Spanish, English, and German are all Indo-European languages, meaning that they are decently related . Spanish came from Latin, so it is a Romance language ;) . English and German are in a different branch as they are Germanic. So sure every language comes with its own set of difficulties. I would love learn spanish too ,moreover your own view was pretty clear and i do agree with it ,and as karl marx says " From each according to his abilities ,from each according to his needs " .