I tried getting an interview for one of those LinkedIn posts and even though I had a really good starting point (successful internship within the last few month

I tried getting an interview for one of those LinkedIn posts and even though I had a really good starting point (successful internship within the last few months plus an internal referral from someone working in the group I applied for plus being a good fit based on my skills and education) I wasn't even invited for a first interview, only got a generic rejection by email. So I don't think these postings are all real.