That's a fair point! It is true that recruiters are human and cannot review 5k applications per week.

I don't mean to say that recruiters must/should review all applications, because indeed this is sometimes impossible. I'm just saying that, as a recruiter, your job is to review applications and you should therefore not be making things harder for the applicants.

Asking for someone's favourite GIF to filter out junk applications is a great idea. This does not detriment the applicant, and it makes the recruiter's job easier. This is good. Making all applications mail-in is not good, because it detriments the applicant (by way of costing significantly more time and some money), while also not solving some of the larger problems when it comes to the job application process.