You'll have literally one thousand resumes to sort through, and of those, roughly one thousand are terrible, poorly-written, undirected resumes from unqualified people. You have a few seconds at most to decide if a given resume is worth even reading, and you're in a headspace where you're pretty certain the answer is "no".
In that atmosphere, the chance of me looking at your undirected boilerplate resume with no cover letter and deciding that hey, this guy stands out, is exactly zero.
Try it yourself if you want. Better still, look at all the people who can't find a job in this industry, and the tactics they're using to market themselves. Chances are you'll discover a lot of them using the "send the same resume to every single job posting on monster.com" method that you recommend.
And they're going to stay unemployed until they change.
It is far, far too easy and too tempting for applicants to fire off a resume and cover letter that is ill-aligned for the position, overly generic, rife with mistakes, or a mix of all three. The humans screening these documents are looking for an excuse to EXCLUDE you: spelling, a sense of appreciation for the role and the business, and professionalism are all key here. Look, finding a job is work. The courting process is involved and is much more than just a submission of a resume. A gross rule of thumb: treat finding a new job like finding a life partner. There are steps involved, and care and feeding along the way. However, you'll likely find dividends down the road.