ISP operations/back-end systems perspective, there's indeed tons of RRA files out there still getting charts drawn based off them with rrdtool, but increasingly everyone is trying to store metrics in things like influxdb and draw them using grafana. Or similar. Even Cacti, a truly old and crufty thing that's been around for a long time has migrated to drawing charts as SVGs.
Don't worry, I'm sure we can teach a slop generator how to emulate this style. LLMs already know how to use rrttool and mrtg! Coming soon to an Internet near you, faux-historical slop writeups.