I've been blown away at the AI upscaling on the Nvidia Shield. On my fairly large 4K TV, the Shield can produce picture quality that looks incredible out of source that isn't all that great. On that note, the Shield has been an unexpectedly great purchase over the years. Long life of support from Nvidia, runs Google TV, works incredibly as a gaming console for Steam Linking into my PC and/or playing compatible Android games, and hosting a Plex server (although I now use Jellyfin hosted on a raspberry pi). If Nvidia would open source their Linux driver (or at least drastically improve support), I'd be a huge fan. I highly recommend, despite the fact that I'm mad at them for the pain they cause me on Linux. Buy AMD cards if you run Linux).
I also have an Nvidia shield that now sits unused for the simple reason that Google forced ads onto the home screen.
It used to be that the Shield was the one bastion away from ads on Android TV, then with one update that somehow manages to reinstall itself despite being completely disconnected from the internet, there are now permanently ads on my Nvidia Shield TV.
I honestly don't know why it's such a big deal for me, but I basically never use it anymore. It's real shame, I got a lot of good use out of it, because as you mention the support has been going on for years now. But I will not subject myself to ads if I can help it. I pay for Youtube to avoid ads, I pay for Twitch to avoid ads. I can't pay to remove ads from my Android TV homescreen (that I didn't even have for the past like 5 years)
I've been a year or so using Sponsor block in addition to basic ad blocking. Now any device that doesn't offer both simply is a complete non starter for me.