What benefits would a hardware upgrade bring the end user? Not releasing a new model every year sounds like a perfectly good thing to me as long as they keep updating the software without introducing performance problems.
My biggest gripe with the Shield is the newest one has a remote that I really don’t like. Luckily it can be replaced with a third party remote!
I too think yearly updates are a bit too much and I too want to keep my devices for a long time. Still rocking an iPhone 12 (mini).
But support for newer codecs like AV1 and general hardware refreshes to keep up with the underlying Android base would still seem like good ideas to me.
Reading the specs it seems that the Shield also would benefit from being able to detect frame rate to auto-switch via HDMI.
Higher network bandwidth to play UHD Blu-ray rips seems like something people want.
Same, one of mine is from the initial models, and still working and receiving updates... it doesn't have the 4k upscaling of the newer models, but I've been happy and have several in my house.
About half my watching is YouTube on a paid account, the other half via Kodi and the high seas. My SO uses the regular apps for Netflix, Amazon and HBO currently. Having support for hacker-friendly features as well as blessed apps with 4k support has been pretty great.
As another post mentioned, the remote (current and previous) have been less than stellar... I've been using the one linked below[1], which works pretty well, though uses a USB dongle. FWIW, can also pair a bluetooth headset if you want the big screen experience, but don't want to blow out the house with audio sometimes.
1. https://amazon.com/dp/B07RFN8Z47