Why is it so hard to update Nighthawk C7000V2 firmware and app misdirection?

From what I understand (and I'm not a networking systems guru), the manufacturer is not the issue, so switching to a different company won't help.  *All* manufacturers adhering to the "docsis 3.0" cable modem/router standard operate firmware updates the same way.  The ISP controls the disseminationn of the updates and work directly with the manufacturer to achieve the appropriate update.  The most the user/owner of the modem can do may be click "update" to the current dissemenated version.  Once done, you don't even get the that option and it's all automatic and controlled by the ISP.

I've having the same issue, btw.  Comcast/Xfinity is claiming they don't have control of firmware updates and recommending that I rent their modem/router.