the way they treat Meg on FG is a reason why FG sucks. The "family" isn't a family at all. it's just a group of one liner bots that live together. compare it with the Simpsons or Bob's Burgers, those are families. Family Guy is dog shit.
I think that's a great comparison - the Belcher's feel like a family, with all the weird love and spite that comes from your immediately family. MacFarlane's shows are just collections of character archetypes (both Family Guy and American Dad, though I feel AD does a better job making it seem like a family) so it never feels like a family ragging on each other. At least in American Dad it's not "Ugly fat dad with fit hot wife"...
As for OP, it does annoy me but it varies by show. Rick and Morty I don't see it as crapping on Summer specifically, Rick craps on everyone at some point and Summer comes off as one of the more sane ones with most of her issues just being typical teenage stuff. Jerry gets most of the piling on and Beth is sort of the "Yeah, don't fuck with her" type.
Always Sunny really comes down to "They're all terrible people doing terrible things to each other". So while Dee gets some gender specific shit because she's the only woman it's never felt beyond the pale.