I thought the Brady kids were actually very realistic. I read somewhere that they made their own props (if they needed a basketball, they brought a used one from home, if they needed a sign, that their character made, that actor actually made it) and chose their own clothes for the show, so that may have been part of it; but they got upset at things like being teased over stuttering, or being compared to an older sibling, and it was of earth-shattering importance to that kid. Their problems didn’t have real-world gravitas, like getting molested, or having a friend die, or even having to participate in some kind of charity to end world hunger. You wouldn’t have even known a war was going on, because honestly, the Vietnam War didn’t weigh heavily on children unless they had a parent overseas. Many were barely aware it was happening.
I think this is one reason the show has been in constant reruns since it went off the air. Technology and the political landscape change, but the sorts of things that children worry about don’t. My son worries about a lot of the same things that troubled me when I was eight. I work very hard to remember how important those things were to me when I was eight, and not dismiss them not that I have perspective on them as my own problems; the point isn’t what I know now, but what he is going through.
Also, the kids were allowed to yell at each other, and get into fights over stupid things, and cry over things kids cry over, and not for adult entertainment, like when the kids on a show for adults fight over something trivial (think, Modern Family), but as a catharsis for the child audience the show was aimed at.
Children on most shows are either too precocious, too evil, or too dumb. It’s OK on a show for adults where it’s played for laughs, especially one where the adults aren’t very realistic either, but it’s unforgivable on a show for kids.
I always related really well to the younger daughter on One Day at a Time. She was about four years older than I was, but I still thought she was a lot like teenagers I knew. The older daughter was too old for me to relate to, but I didn’t find her unrealistic. There were a lot of things about that show that were unrealistic-- the newly divorced mother with no college found a good job way too easy, and was too much at ease in her single-parent role from the start, but I didn’t pay much attention to that.