Is cover letter still worth to send in job application?

If it makes it to a real person and speaks to specific qualifications referring to the job posting - Yes.

Do not tell them your life story.

Explain why you are qualified for the job and cite examples.

If you have been networking beforehand especially and find out some real-world problems they are having, you can speak to how you solve those problems and bring value to the company.

I have a generic cover letter for ATS but I always, always write custom cover letters if I'm handing my application via a person (e.g. a referrer). I investigate what issues I can help solve and bring them up in the letter along with all my experiences.

Hope that helps!