My point exactly - there is not a real world situation where the pi's don't function more than adequately. Most of us will not be using 4K for a very long time since there is no 4K broadcast content and no broadcasters are planning to migrate in the near to medium range.
I wouldn't go that far. UHD is an issue - it just isn't an issue for everybody, and if it isn't then the Pi is still a sensible platform to consider.
However your point about broadcasters and 4K is a bit wide of the mark.
The BBC have already broadcast 2160/25p 10-bit HLG HDR Blue Planet II as a trial on iPlayer, and they also trialled SDR UHD clips of Planet Earth II before this. (Both have had UHD Blu-ray releases)
My understanding is that the BBC will trial 2160/50p 10-bit (possibly HLG HDR) live broadcasts on iPlayer later this year. There are a number of events the BBC has rights to that will have a UHD host broadcast feed available, and the BBC could make this available via iPlayer.
The BBC is already shooting most Wildlife content in 4K/UHD, and similarly any high-end drama that could be co-produced or sold to a 4K pay-TV platform like Amazon or Netflix is likely to be shot and edited 4K (even if shown HD on BBC One/Two)