Sibling choices making me upset?

I have two siblings who are just a little bit younger than me. I am twenty-six years old and my sister is 24. My brother is 21 years old.

My sister is currently finishing up her bachelor’s degree in some art field and now applying to get her masters degree in Art Therapy. This is extremely dishearting to me not because she is doing something she loves but rather she is taking all this time she spent in college for a useless degree. I have even asked her numerous amount of times what her plan is to do with the degree and she has no idea. This is extremely scary and nerve-racking for me because I hate seeing someone especially my sister have no plan at all. What is even worse is Art Therapy was ranked in the top ten for worse degrees to attain. It annoys me because my sister is a very smart person and did outstanding in high school. I just can’t seem to grasp or understand how it came to this. She is going to graduate when she is 26–27 years old with a degree that is pointless. The demand for the degree is extremely low and the pay for the degree is horrible. It starts out at like 22–24k a year and the max ranges from 44–55k but that is years and years of working in the field. I hate this because nowadays this is not an income that is liveable on and I know she will be by herself because she just stays inside all day and studies other than going to school. She is very shy and I do not see her ever getting married or finding someone. This makes me very depressed because all I am seeing is a failure when I hate that.

Me personally I am currently pursuing an associate degree in nursing. Then I am planning on doing travel nursing while working towards my BSN and eventually get my masters in NP.

My brother, on the other hand, is pursuing a degree in software developer which is a great field but he is not very determined. All he does is stay inside all day and play video games. He does not currently work. He does not seem like he is taking initiative to get his degree as soon as possible and he is not even looking for apprenticeships. On top of this he literally just went out the other day and bought the new iPhone X for 1,000 dollars. This annoyed me and I could not believe it.

Am I putting way too much on myself and should I just focus on myself? I am extremely worried about my brother and sisters future. I want them to be successful but the way I see it right now I do not believe this will happen. Anyone have similar situations and if so how did you handle? I hate having my parents deal with this.