I'd love to buy a newer, better streaming box than the several I already have but after spending quite a bit of time investigating, the state of Android TV-based streaming boxes & sticks is awful. That's one reason NVidia's Shield (Tegra X1 SoC) is still well-regarded despite being a circa 2015 design (the 2019 rev was just a cost reduce/bug fix with the same performance).
Beyond that your choices are to either stick with the same mainstream Google/Amazon/WalMart boxes which are locked down and based on 5+ year-old SoC designs or go with second-tier boxes from Asian vendors on AliExpress/Amazon/eBay, all of which have some different combination of significant compromises:
* Don't work with certain DRM, streaming services or codecs
* Has unreliable manufacturer support (certain firmware works with some DRM/services, next rev fixes one but breaks another)
And even those are built on old hardware designs because there's been no significant advancement in set-top SoC performance for over 5 years. There are only a handful of set-top SoC makers (MediaTek, Amlogic, Rockchip, etc) and while they do occasionally introduce new chips, they mostly only update the video decoding block to support newer codec levels or DRM revisions while keeping the same ancient ARM CPU/GPU cores (or different cores with the same class of 2015-2018 performance).
A good example is the Ugoos AM6B Plus box someone in this thread mentioned as an option for certain use cases. It's been verified to decode DV7 with FEL BUT only works well with local files, not streaming services. And the Amlogic 922x SoC in that box is 5+ year-old tech (I have the same chip in an Amazon Fire TV Stick 4k Max (2nd gen)). The hardware performance of these boxes has been essentially frozen in time due to a 'perfect storm' of factors:
* Most consumers want the cheapest box they can get which plays the main streaming platforms (NetFlix, Amazon, Apple, Disney+, etc). As long as they get a picture of minimally acceptable quality, they don't know or care if the hardware/firmware/drivers properly support the better Dolbyvision levels or adds the enhancement layer or supports ICtCp color space, 12-bit tunneling through RGB or if it handles Source-Based Tone Mapping (SBTM) correctly. They also don't care about playing locally hosted files smoothly or horrendous latency in the Wifi/Ethernet driver stack that nerfs local game streaming.
* DRM is a shit show. The big Hollywood studios require streaming platforms to use specific encryption. So the streaming platform apps will only playback streams on SoCs which have been officially certified (or they nerf the stream to 720p). The certification process is onerous, costly and time-consuming for SoC makers.
* SoC makers, having run the certification gauntlet a couple times now, would like to do it again, approximately... never. On top of that mess, developing and maintaining firmware for their decoding block which properly supports the constantly evolving landscape of divergent codec levels, enhancement layers, color spaces, tone mapping, etc is hard, expensive and requires deep expertise across multiple domains. They just want to sell trays of cheap SoCs and see all the rest as a bottomless money pit eating their slim margins.
NVidia did all this with the Shield and it's grandfathered in on the DRM and they've done a decent job supporting some more recent codecs, levels and layers where they can. But the Tegra X1 platform is 10+ years old now - yet it's still slightly more performant than any other DRM-certified SoC to this day, which just shows what a mess this is.
Which is insanely frustrating if you understand technology platforms, care about actually seeing the full quality modern tech can deliver and would like to do so on a non-ancient hardware platform capable of other trivial things like locally streaming files with actual throughput >100mbps or streaming games with non-glacial latency. But that's just table stakes because the things which could be done with more modern hardware are super-interesting, like AI-based upscaling, frame gen, removing compression artifacts, reformatting content, on-device gaming, etc.
But using standard small form-factor PC/GPU hardware is a non-starter because of DRM certification. So... it would be great if NVidia would make a new Shield based on the new Tegra. But that's a huge new effort and, sadly, NVidia would crazy to divert resources or wafers from the AI-bubble cash printer to anything else - so I highly doubt it's going to happen.