These interviews are looking for specific things while you work through these problems. They do not necessarily want you to answer the question exactly correct. They want to see you work and see where you are at.
Intro level jobs are competitive right now. The search will be slightly harder but there are still jobs out there.
Know what is happening in these interviews before you go into them. There are a number of books specifically about code interviews and how to pass them. Read them. STUDY FOR THE INTERVIEWS instead of complaining as if you are owed a job.
None of us like the whiteboard interviews. It is a good dog-whistle for a good education which, despite what people say, is still worth something to these companies.