It's still available. Most WF gear isn't BiS anymore, though. They can still be farmed through WoD dungeons (slagmines, iron docks etc.) through warforge procs . The composite stats from socket TBC gear edge them out statwise this expansion.
In dragonflight, WF gear was BiS and it was a brutal grind. It took hundreds of runs to get full WF gear and even more to get sockets/tert stats. What you're looking at is probably someone who had their character at 11 through DF, did the grind and is still running with the old gear.
There's still a few things that are worth farming (Enforcer's Stun grenade, bracers with sockets/tert etc.) but it's not worth the time investment anymore. Socket gear is better in most cases and is a lot less time consuming.
(At least, that's how it was for 20's so I'm assuming the same is true for 10s/11s too)