Mail service and telephone service are effectively universal, so a job application via the mail or the phone is within reach of basically everyone. Having a handset and a phone line is also much cheaper than owning even a second-hand smartphone (at least a decent cellular plan with data isn't very expensive anymore). A deaf person could handle applying by phone via a relay service (though these days they probably can't because relay services are abused by malicious parties and everyone hangs up on them). Paper applications were probably very tough for blind people though, I'm not sure what the solution was... the internet is likely better there, if you're lucky and the job application website is actually accessible.
I lived in a very rural area for about 50% of my childhood - we had no fire department, we relied on a well for water, our town's official population was in the hundreds, etc. If we wanted to get on the internet we had to do it at around 38400 and random packets would get corrupted because the lines were old and low-quality (I wrote my own parity tool in VB6 so that I could download a file 3-4 times and produce a not-corrupted version). Despite that, if I wanted to call someone up on the phone to speak with them or send a letter, that was just as easy and effective as it was when I lived in the suburbs.
When we eventually managed to get slow DSL years later it was INCREDIBLY expensive because in rural areas if you're lucky enough to have service at all the monopolist who offers it knows they can charge as much as they want.
A library is not a building. What if it's cheaper to make it so people can call and make an appointment with a librarian, who will come to your house and assist you with your government service needs?
