Because EVERYTHING WAS DESIGNED IN THE LATE 60's and early 70's.  Most of their equipment is over 50 years old and it breaks down regularly and no one these days knows how to fix that stuff!  A few old-timers that are still around at the IRS know, but they are few and far between.  But just look at the increase in population since the 1970's?  And we wonder why things are in a mess?  OBAMACARE ADDED THE BIGGEST BURDEN TO THIS NIGHTMARE (another damned good reason to get rid of it because it's a pain in the ass).

https://www.washingtonpost.com/outlook/i-was-a-drug-rep-i-know-how-pharma-companies-pushed-opioids/2019/11/25/82b1da88-beb9-11e9-9b73-fd3c65ef8f9c_story.html

This is really interesting reading, and the format of the article is also quite a nice change from the usual "read a paragraph but don't remember what I read when I'm done" paragraph!  Most article are simply too dang boring to read.  This is a format lots of onliners should be looking towards.