I adored Steptoe, although I never understood (I was too young) at the time just how wonderfully written and acted it was.
The essence of the set-up is the same in all great comedies - the protagonist(s) is trapped, seriously trapped, and they know it.
This applies to all the great comic characters, both Steptoes, Meldrew, Hancock, Perrin, Fawlty, Brent - I am sure there are many more.
But as far as the Steptoes go - Wilfred Bramble's facial expressions were Brechtian in their emotional range and impact.
I also recall watching one episode, and realising after that the entire thing had been shot with one camera, no edits.
I had just watched a classic theatrical 'two hander' in the guise of a sit-com - and just how wonderful it was.
Blacker than black - and a level of quality that is sadly missed.