"Are people mass-spamming applications or something?"

since the dawn of time (1970, jan1)

Well, in 1970 you could only do about 10 a day, because you needed to type a cover letter with the hiring manager's name in it. Job search (newspaper "help wanted" ads), envelope stuffing, trips to the post office and so on took time too.

Photocopies were low quality and looked obvious and got you into the trash straight away.

So mass, but compared to population not very mass.

The real start date was Eternal September.

If I was getting hours and hours of interviews, an hour of paperwork would be trivial.

When 2/3 companies don't even bother sending a rejection email, I tend to not bother doing the 20 minute job applications.

When you see a job and it says '3000 applicants so far' or something, this is why