How much do job applicants get paid to apply for jobs? How much effort do you expect them to put in, unpaid, to kiss your butt, specifically, when there are hundreds of companies that are just like yours? Many of those companies will simply ghost the applicants that put in extra effort to tailor the heck out of their resumes. There is no expected payoff for tailoring until after the company actually makes contact, using a real person, and by then you're already interviewing.
It would seem then that the best solution for the applicant is to create a program that reads in an advertised job posting and automatically tailors the base resume to it, so it looks like they put in effort for each company, but actually just did the work once and used the automated solution for everybody. That sounds like more fun than hand-tailoring resumes, anyway.
Given that none of us get paid to look good for potential employers, what sort of reciprocal effort does your company put in to tailor its recruiting to specific applicants? Are you saying that companies who don't actively recruit specific individuals from leads will likewise be overly passive when it comes to retention? Because that... seems accurate.
All you really know from an untailored resume is that the applicant didn't see tailoring to your company as worth the effort.