I mean, they fell by the wayside because they were replaced with discount versions of themselves.Etta developed an eating disorder, and her desire to lose weight happened in the Perez run. With her citing a desire to have a body like Diana's when she was younger. In the Jimenez run, she looked at her wedding album with Lois and expressed a bit of annoyance that people had been looking at Diana more than her. Etta didn't appear much post Crisis, but these issues seemed to crop up whenever she did until Simone got ahold of her and injected more of her Golden Age personality into her. Not that exploring these topics is an inherently bad idea, it just never fit the character Etta was designed to be.
Lois and Jimmy absolutely do have personalities roughly equivalent to someone like Etta. It's why Lois in particular has been a continued part of Superman's adventures, her chosen profession and willingness to throw herself into danger keep her involved in Clarks superhero adventures even when the context of love interest isn't factored in. Jimmy is a fearless photographer who takes his constant weird ass transformations in stride, and likes to dress in drag. He doesn't get much use these days, but when he does in stuff like All Star and his own recent series, it's always well received and has it's roots in all that crazy stuff. Julia and Vanessa work great in Dianas early years, but a single mother with a teenage daughter don't lend themselves as being free to participate in the Acton adventures Diana needs to take part in, which may be why they fell by the wayside unless angst can be wrung out of Vanessa's traumas.