If you are being invited for an interview they want to hire you. There is no other option.
You might be nervous, you might be late, you might be any number of things but if you can do the job, you are in with a really good chance, the interview is your opportunity to prove that you can do the job.
You might be interviewed by someone who is an accomplished interviewer who asks insightful, thought-provoking questions or you might be interviewed by a complete beginner. Either way if you demonstrate that you have the skills do the job, they will be interested.
As an employer they want an easy ride, they want to hire people who are easy to manage, people who are punctual, people who are enthusiastic & positive, ideally people who have potential to progress. They are probably not that interested in moaning, groaning, sickies who hate their previous employers, have never been promoted and blame everyone but themselves!
As an employer I have hired 100’s of people, but I never hired anyone who wasn’t positive, simply I only wanted to work with positive people.