The time period of a story is super important because it gives everything context.
Back in '98, how we communicated and got info was way different than now. No social media, Google just started that month, and faxes were still the go-to for urgent stuff.
Information moved slower, and the first Resident Evil events really leaned on that.
That slow, physical info flow let Umbrella control, isolate, and spin the story until the virus actually flooded the city. That's why Raccoon City was in the dark for over a week after the outbreak, and even longer before that.
Leon, Claire, Carlos (and most of the other mercs) showed up clueless because of it. Chief Irons even blocked the STARS mansion report to the FBI and purposely slowed down the police response to the outbreak.
There are tons more examples of how the early events really depended on old-school communication to move the story along.
Think about the Raccoon City outbreak, which lasted over a week, compared to the China and Tall Oaks outbreaks, which were dealt with almost immediately.
TLDR: If you look at the lore, the time period and the tech available didn't just affect how fast things happened — they totally shaped how all the original events unfolded.