This looks like the upper limit for WeWork. It doesn't matter how much nicer looking their offices are or if they have free beer bashes and parties, those expenses are all tiny when it comes to the bottom line of a multibillion dollar corporation.
Plus, Regus has more desks and branches than WeWork, and is orders of magnitude less expensive.
Just as a thought experiment, imagine that Regus ended up just straight out getting all of WeWork's assets in some sort of liquidation, and half the tenants stayed. They would get bigger!
There is a possibility that WeWork can tap into more interesting markets.
Purely annecdotal, but the people I hear about who ending up in WeWork used to be in either dirt cheap local coworking spaces, or just getting their own offices. It does feel like a "pie got bigger" sort of thing, that wasn't before captured by such a large player.
If WeWork get all Regus assets for free and half their business, sure, why not? That would be an immediate 3-4 billion dollar injection. As it currently stands, their coolness(tm) is not enough to compensate for their bloated fees and limited office space locations.
WeWork can't keep it up forever. Eventually they have to raise prices and/or cut perks (probably both).