„keep old content relevant“ is a pretty vague thing to point at.

It's not vague at all. We are literally in a thread where people are asking to return to Suramar. Have it be used for something. Have a rebuilding process going on that players can participate in for rewards, overhaul it as a new zone with exclusive content for crafting professions. Do it again with Undercity, Gilneas, Teldrassil. Blizzard has just destroying zones for the "shock" factor for years instead of giving us real reasons to go back to them.

There's a thread on the front page right now asking why the fuck the brutosaur was removed when that's a piece of content that could have kept people playing.

"Better writing"

really isn't as vague as you think it is. Everyone mutually agrees that the expacs I listed had better writing than BFA and Shadowlands, so clearly there is some metric to judge that by. They need to stop throwing giant, world destroying villains at us left and right and take us back to something simple and start building up from there again. This time give us characters we can get attached to who aren't dumped the immediate second you finish their questline, but they stay with us through the whole expansion and beyond.

The story would actually benefit massively if they just came out and said Shadowlands was a N'zoth dream and not canon.

I swear bro it gets good around the fourth expansion

It gets good in the first expac btw :)