Like you post
If 99% of the computers out there CANNOT take advantage of that speed.( I have the ethernet port that support 2.5gb)
Why would they service 2 gb?
You know what ? Maybe I just need 1gb
but that's not the point.
I signed up for 2gb service and there is no way that I could get the speed they advertised With setup provide by cox even if I have 1 pc and one phone.
They should advertise like this "we have new 2 gb speed service but you still going to get around 600 to 900 99% of the time with your wifi and there are no options for ethernet connection provide by our xb8 router.
The current setup clearly isn't meeting expectations but there's nothing holding you back from getting the provisioned speeds. Having a 2Gbit connection allows a combination of devices to run simultaneously with little risk of slowdown. You should for example, be able to run 2x1Gbit devices simultaneously with little noticeable slowdown.
Another option available would be to just purchase your own router that meets your specifications if you want 2Gbit speeds from a single device.
You are forgetting that the speed is shared across your devices. With 2gb speed, you should be able to utilize multiple devices with very little slowdown on them. Like ExtraChrispy said, 2x1gb devices simultaneously, or you can have a couple of your tvs streaming 4k and use your computer without seeing the tv's buffering.
