Sent out 80 applications with a custom cover letter for each one and got ZERO callbacks.
I spent like 3 hours on each cover letter tailoring it to the job description and I got absolutely nothing back, has anyone else tried this approach and actually gotten a response or is it all just a waste of time?
Spent like 3 hours on each cover letter" - there's your problem man. Nobody wants to read a novel about how much you want to work there. Recruiters spend maybe 10 seconds glancing at that stuff. You should have blasted out 80 applications in a couple hours with a simple template, just change the company name and one sentence. Hanging your hopes on cover letters is old school thinking, most hiring managers don't even read them.