I have Gigspeed internet service, why is my upload speed limited?

The advertised upload speed for the Gigabit Speed Tier is 35 Mbps. With their 20% speed overprovisioning, the upload speed should be around 40 Mbps.

You missed the point of my question. Why is my upload speed so limited. Since I have a higher speed tier, Comcast should be offering a higher upload speed to keep pace with the download speed. It's like fiber to the house. They have the capability to have fiber to the demarc on the side of my home, but Comcast refuses to install it. I'm tired of having old tech when I need the higher speeds since I work at home full time.

And please do not suggest Comcast Business. It's not available in this area.

@JohnMatteson You're getting 38-40 Mbs upstream?  I just upgraded to Gigabit and am only pushing up 5-6 Mbs max. with the Xfinity gateway acting as the router, or in bridge mode.  What I wouldn't give for 6-7x performance on the upload side...

I have as little Comcast equipment in the house as I can. For internet, the only thing is the modem, which I own. All the wireless is provided by an ASUS router, that my son configures. When I plug my computer directly into the modem, I get a couple of extra megs per second, but not enough to make a difference. When I took a look at Comcast's Business Gig speed, I was surprised that the upload speed was the same as I have now. When the heck will my upload speed match the download speed, or at least come closer to matching.

The current upstream / return path bandwidth spectrum allocation on DOCSIS is physically limited. It's the current nature of the beast. This is why there isn't as much flexibility with offering faster upload speeds compared to the download.

Here is an informative article about the future for the upstream bandwidth capability for DOCSIS based systems;
 
http://www.multichannel.com/news/distribution/comcast-eyes-upstream-expansion-it-pulls-fiber-deeper/411718

http://www.cablelabs.com/innovations/docsis3-1/

 They do offer a 2 gigabit (with symmetrical speeds) FTTH (Fiber To The Home) service in some areas.

https://arstechnica.com/information-technology/2020/10/comcast-says-gigabit-downloads-and-uploads-are-now-possible-over-cable/

All well and good, but all of Comcast fiber stops at the county line. There's fiber to the breakout box on the side of the highway, but it's too far to run fiber to my house (I'm 1.3 miles from the breakout box). Google Fiber stops a bit closer, but still doesn't cover my neighborhood.