I'm from the UK and another age 8)

I applied for about 50+ jobs as a graduate engineer in 1991. Back then you wrote letters. Hmmm: You printed letters - mail merge was a thing.

You signed each one by hand, with a quill pen and used a wax seal and cast a Spell of Engagement.

OK, you signed your covering letter with a pen (might be a Biro but I did use a Parker and Quink, myself) You also had to put your covering letter and curriculum vitae (CV == resume) in an envelope and pop a stamp on it (2nd class) and post it. None of that Linked In bollocks.

Your covering letter would be bespoke to the company approached. You did some research and mentioned something pertinent.

Nowadays I'm the employer.