I'm a web developer who's having a similar experience. I'll tell you something that you may or may not find heartening. My 3-paragraph cover letters aren't doing jack for getting interviews. On the other hand, clicking the "easily apply" button on indeed or wherever, assuming I'm qualified for the job, has yielded at least a phone call in 3 of the last 5 times I tried it (this month). No cover letter, just maybe two sentences about who I am and why I'm interested.
It hasn't gotten me a job yet, mind you, but phone calls are slightly more encouraging than silence.