I'm embarrassed to say that I used to love watching Frankie Boyle. I've changed my outlook on life now and just don't find his nasty material funny at all.
As for left-wing comedy, it's been taken over by NPC's who've been programmed to seek legimitacy from the establishment IMO. There's only so many times you can slag Donald Trump before it loses it's appeal.
I think the bias toward the left has become so pronounced these days that even the slightest hint of moving toward fairness is often seen as right wing bias. This is why the Daily Mail is always labelled as right wing when it's clearly not.. it's just a sensationalist rag.