Few reasons for this.
A. "Pager" is basically used to refer to Discord cuz theres no reason to bother using it cause to some, it seems highly redundant and 1980s actaually had a Bulletin Board System, as Well as Usenet, so while technically not discord, message boards did exist in the 80s.
B. The pager system could really use a "copy to clipboard" or "type out pager information" button like the phone has.
C. The pager system in general kinda needs a refreshment/overhaul, cause from what I can tell, nobody ever uses it except for maybe 1, 2 emails between future contacts every now and then.
D. Extra: I understand the "deafen in discord" rule when being mugged, but a trade deal? Wouldint it make the deal/trade itself more efficent and streamlined, plus it could be the temporary member system Discord ALREADY HAS? They join, join a vc, do the deal, it happens in-game, then they leave the discord server, badda bing badda boom, shit gets done.
(Extra aside, this issue also exists with the underground rumors chat. Make an ad for your drugs and shit? 50% of the time, nothing happens, you just wasted 100 dollars on it, and nobody responds because "police could be listening in/nobody trusts it" despite police never having access to it anyway unless they bug a brick phone which gets swapped after the 2nd weak, dropped in the ocean somewhere, and nobody would realistically grab it because its a burner phone. The other 50% is full of that chat calling you/others "feds" aka rats for no apparent reason. Honestly, if the only way cops can find out is bugging a phone via unscrewing one of the ends, putting in a bug, then screwing it back on (which could probably be noticed after a while or the phone would be chucked anyways because you're replacing them every 2 weeks as a security measure, or even shaking the phone/trying to find it), then listening in, and the radio issue is fixed by changing frequencies, why do people not trust rumor chat nearly at all? Are cops just always listening in 24/7?? This the 1984 novel??