Hmmm. this article from 2011 says they do: https://web.archive.org/web/20130504074926/http://gulftoday....

This company is still advertising its tanker services in 2020.

https://dotless.ae/how-does-dubai-manage-its-sewage-water/

From 2016 so Dubai may have had a working sewage system for a year, so I could be wrong.

> Dubai: The emirate of Dubai will get a new deep tunnel sewerage system costing Dh12.5 billion in the next five years to replace more than 121 sewage pumping stations.

Pumping station meaning tankers transport the waste away.

https://gulfnews.com/uae/government/dubai-to-get-a-new-sewag...

From the end user perspective that still seems like a working sewage system, no?

It’s not like they’re making residents pay high taxes to pay for the tankers either.

We disagree on what a working sewage system means. Tanker trucks aren’t it. Dubai may have had a working sewage system for a year now. Not great but better than I thought was the case.

Your definition involves strange mental gymnastics to turn a perfectly functional albeit expensive sewage system into a non-working sewage system.

The end user experience of the sewage system in Dubai is no different than in regular Western cities. That’s really all that matters when trying to figure out if it’s “working” or not.