As far as 7pm goes, I don't know about early evening hours. I drove to WAS and parked in the garage November 2021, at 3:30am. I went through the station and took a walk towards the Library of Congress. When I came back an hour later, they were checking tickets at the main entrance. No zombies present inside.
The story of WAS may be filtered for many by the fact that it was a surprisingly popular mall and movie theater twenty years ago, after decades of lull. Like many such places, it no longer is, so that gets wrapped up into an exaggerated story of decline. The main thing it is in normal hours is busy. Train stations should be safe environments., agreed.
Back pre-2019, when I was still working, I would take a 7:10 PM Regional out of Washington a couple of days a week. Back then, the evening lineup ofr Amtrak was something like 1900, Acela, 1910 Regional, 2000 Acela, 2045 Regional, and then the 10 PM overnight Regional to Boston. There were arrivals from the north into Washington at 1952 (Acela), 2005 (regional), 2047 (Acela), 2102 (regional), 2140 (Regional), 2152 (Acela), 2202 (Acela), 2220 (Vermonter), 2317 (Acela), 2325 (regional), 1225 (AM) regional, 0125 (AM, regional).
There were also a few MARC trains that left after 7 PM. Not sure about the late night VRE service.
Back then there was quite a bit of rail traffic in and out of the station after 7 PM, even until the very early morning hours. It was only empty from 2 - 5 AM or so.
Covid killed most of the post 7 PM northbound train service and cut back some of the late arrivals from New York and Boston. Back in 2021, I once did a transfer to the Palmetto (departs 2030) due to a very late Capitol Limited, and Union Station was really, eerily empty. A number of the business were closed down from the lack of traffic (especially the fact that MARC and VRE weren't dumping hordes of commuters into the place due to work-at-home.
I started noticing more homeless people hanging around the station starting in 2017 or so. It also seemed like the business at the food court downstairs was dropping off after 6 PM, except when school groups were having their spring class trip to Washington. The homeless people weren't very appealing to look at, but they never bothered me.
I think the station is now rebounding, except that when I pass through now, it's usually in the morning or during the middle of the day. They did open a new eatery on the main level (Caine's chicken), but there are still a lot of closed businesses in the downstairs food court. I miss the old Center Cafe in the Main Hall, which was a great place to get a martini while waiting to board the train.
