For some shows I’ve noticed that it’s not too difficult to get around half of their seasons in 4K, with the 4K releases for the remaining seasons being seemingly nowhere, whether it be on public trackers, private trackers, or usenet. Doesn’t seem to be an issue of shows only being shot in 4K after their first few seasons, as in some cases the 1st and 3rd seasons may have 4K releases without the 2nd season having one, for instance.