Is all Classic raiding hardcore?

You see all these videos on youtube describing raiding in vanilla and they're talking about all the consumables they had to farm and how everyone is an engineer.

And I watch the fights and these guys are clearing bosses in just a couple of minutes.

It occurred to me that a lot of these video makes are people who have been playing hardcore on private servers for years, who are basically speedrunning the instances.

Is classic going to be full of this? Is this like, the bare minimum requirements for raiding in classic? Or is it just the requirements to be the very best, the best there ever was?

Looking for some perspective on the matter.