Why do you think British shows and specials are so much better then American shows. The productions,

[Ocelot II]

8. It might have to do at least in part with funding.

The BBC is partly supported by user fees paid annually by all users, which support its radio, tv, and online services; it does not rely entirely on advertising as in the US. In the US the shows depend on advertising, so tv writers have to pander to advertisers - if a show won't attract advertising revenue it won't be carried. As a result the writers write US shows for the masses who buy stuff. This is also why PBS' shows are better than network shows - they don't rely on mass advertising.

That said, some of the Netflix and Amazon Prime series produced in the US are very good - but there again, the funding comes from user fees, not advertising.

If you don't mind subtitles, the Scandinavian countries have created some really terrific mystery series, some even better than the British stuff.

And don't forget that Americans tend to assume British accents are classy (even though some of them are very low-class), so the British shows carry that patina of class that they don't necessarily deserve (e.g., Benny Hill - you know you're drunk when you start thinking Benny Hill is funny).