Referrals by hiring managers who I have previously worked with and want to hire me aren’t even getting me a phone screen from their recruiters.

The majority of employment in tech is with large, corporate firms, and unless you are in the executive tier they all have implemented a massive amount of process to prevent bias in hiring which means that even networking has low impact on getting a job, beyond letting you know the positions even exist

Yea, whenever someone says "Just network, bro!" they never actually fully connect the dots between networking and walking into the office on your first day of work:

Step 1: Just have coffee with a hiring manager

Step 2: Hiring manager says go check out job #41102, and submit your resume. Good luck, bro!

Step 3: [???]

Step 4: You've got an interview to ace!

Nobody ever explains the [???]. They just assume that by magic, your online submission rises to the top of the stack of 1,699 other online submissions, avoids all of HR's filters, gets to the right person in the right department on the right team, that person has the authority to pick you out of the pile, and so on... There's a lot still out of your control in this process. It's not just Networking --> Job.