tl;dr: there's nothing wrong with generic cover letters/resumes, assuming they contain the information the hiring manager/HR want for each job posting
And all of them have a job atleast somewhere.
The point of CVs and resumes is not to get you a job. It's to get you an interview. You then can sell yourself in the interview and get yourself a job offer.
The reason I point this out is sending out lots of resumes doesn't get you a job, it might increase your chances of getting an interview.
Parallel example
Therefore, what is the point of tailoring your CV and cover letter to a specific company when genericness to a certain extent is more beneficial anyway?
Consider this example. Imagine, instead of typing a somewhat personalized answer directly referencing your post, I just copied text from one of those posts you link and put it as an answer. You'd probably sigh, go "great this isn't overly helpful" and ignore most of this answer. However, if those references you listed were good enough and stand alone, I could just quote large portions of them and affirm them. This would more represent having a great, generic resume.
Same thing is true of boilerplate resumes/cover letters. If you don't have enough interesting skills or experiences to make your resume or cover letter generically great, you're going to need to tailor it specifically. You might even need to do this if you have a lot of experience due to being later in your career.
Incidentally this is the point of Stack Exchange to some extent, providing good, boilerplate answers which comprehensively address questions.
If your resume or cover letter is good enough, then you can use it as such.
But what was also clear is that different hiring managers/HR personnel will be valuing different things on the candidate.
This is a good part of the answer too. A hiring manager is looking for a specific person with a specific set of skills. This will vary somewhat from job posting to job posting.
Other considerations
Keep in mind most interviewers who have copies of your resume will have the version you initially submitted.
If you want to highlight certain things about yourself for that company, having your resume naturally read as such is very beneficial. You can simply talk about whatever is on the resume naturally.
This is considerably easier if one of the following is the case:
- Your resume is awesome in a generic format
- Your resume is tailored to the company you applied for
On a personal note, what I've done before is to keep a "master" version of my resume, which has more detail/information than is necessary. I can then remove irrelevant information to specific job postings easily.