If you have Apple users at home, the integrated experience and the video quality is going to be very hard to match from other platforms. My parents use Chromecast and it takes so many more steps to send content on to their media system. The video quality when casting also suffers a little, though that may be because they’re using cheap ISP router AP combo box, and I’m using Ubiquiti APs instead. Having said that, I do think the A15 processor in the most recent model is an overkill in the graphics performance department, so I wouldn’t completely rule out device capability compared as the cause of video quality difference.

Based on my readings, I think most recent high end nVIDIA Shield Tv Pro is the only closest in terms of raw performance and even then it may be a bit behind. Tegra X1+ found in the Shield Pro is on Maxwell architecture, which is older than GeForce 1080 series’ Pascal architecture, if I’m not mistaken. This would date it to around 2015-ish; whereas the previously mentioned A15 processor in most recent version of AppleTV 4K was introduced in 2021 with iPhone 13 series.