The key thing about Instagram is in the 'Insta' part of the title. It's (supposed to be) about the moment, which makes it very consumable. Scrolling through, you hardly notice that your brain is being bombarded with messages (go on - blow a month's food budget on a must-have Bella Freud 'it's a good investment' jumper / paint your sitting room dark blue / replace all your mugs with artisan grey pottery ones that look good in 'hands from above' pics, cradling a cappuccino)
Because it hasn't been around long enough, we haven't yet really got to the stage where the style we're being relentlessly sold has become laughably outdated. Imagine if IG had been around in the 80s? We could now look back at pouting mirror selfies of instamums in their metallic dresses with giant shoulder pads, trying to sell us pink frosted lipstick and blue eyeliner against a backdrop of lurid red and black striped wallpaper. We'd have the perspective to see that all this 'must have' stuff is fleeting and a fad of fashion, rather than the essentials for a perfectly curated life.
It's the same with children, I think. My kids are a bit older, so I missed the instamum thing for a long time. The first time I became aware of it was hearing the Saccone-Joly guy talking on Woman's Hour with the confident authority of some celebrated parenting guru.
I was astonished to realise, as I listened, that apparently his only qualification was having two (at the time, I think) very small pre-school children. And yet there he was, holding forth about how to deal with sibling rivalry and how to foster good relationships between your children.
It was all so based on a moment - a really short window of parenting time, for children at a very young age. He had no idea how hollow his advice would sound in few years time, and how pitifully simplistic it sounded to the parent of older kids. He genuinely seemed to have no awareness that his children would change, and no perspective that the glossy lifestyle he was promoting wouldn't last. I think a lot of IG parents are in the same bubble of delusion.
Sorry - long ramble. In short, I think that the IG star will fade with time when it becomes impossible to ignore that the 'insta' part of it isn't sustainable. Life scrolls on.