Seems Helltides are empty, hardly anyone does them

The game is likely suffering die-off.

That and people rush through the Helltides, as the only enjoyment from them comes in the form of loot you can gain…

So, you find those Mystery Chests, get them open, then leave. Done.

Here is a thread detailing what I feel would improve Helltides:

The thread about improving Helltides.