You bet, I got my current job with 1 phone call because I knew someone who was starting a company and needed someone with my skills.
If you send your resume to a company where they don’t know you it will sit in a pile with 300 others, if you know someone there who can say “oh yes I know him/her and they are great at X” it will skip that pile and land right on the desk of the person who is hiring. Guess who gets the call for the interview, its not one of the people in that pile of 300 resumes!