Originally Posted by B747-437B

You don't need to "activate" the Emirates ID to use the e-Gate in Dubai. It is now automatic (but the e-Gate machines in SHJ/RKT still are not compatible with the EID). But you can also pay the AED 200 or similar to get a separate e-Gate card if you want.

The benefit of getting the physical e-Gate card is that many airlines and countries will not allow you to board on the way back to the UAE if you have a residence visa and no exit stamp from within the last 6 months. They demand to see the physical e-Gate card. I've even had the issue with flyDubai in Entebbe where I had exited the UAE from Ras Al Khaimah as a crewmember without a passport stamp and I was only cleared to board at the absolute last minute after the station manager called the security department and they took copies of my e-Gate card. Without that, I would have been denied boarding. Similarly, I always get queried by Indian immigration for my exit stamp and they ask to see either my departing boarding pass from UAE or the e-Gate card. Rwandair security in Kigali also does this.