Total BS. You can have a ton of toons and mats, etc without making a lot of gold.
Everybody plays different and every playstyle matters same like the one you did choose. 
I totally agree with Xenophontes here.
If I would buy 5 Tabs, my take on them would be:
Tab 4 + 5 => Mats (new ones and those old ones I need for things like goblin gliders, etc)
Tab 2 => consumables (food, potions, flasks, goblin gliders, drums, etc)
Tab 3 => consumables that didn’t fit into tab 2 + gear token + warbound gear
Tab 1 => space for exchanging things between chars + bank chars, etc + space for things that I didn’t list, but might still come, etc, etc
And yes, not every single slot in every tab will be filled for organisational purposes, but that’s no different from how most people use bankspace in WoW.
So filling up 5 tabs only with things you might need for your twinks is pretty easy to do without it resulting in hoarding is not an illusion. And it would make sense.
But with the current pricetag? Haha, no way I even buy the 4th tab, probably not even the third. Even though I could easily afford 4.