My kids are exposed to nature and natural tanks a lot. They play with trash, and about anything else they can grab before I take it away. They have plenty of plastic and other stuff in the form of toys they touch and mess with, they do not get to touch the inside decore in the tank(yet).
One view might be this keeps them interested in the aquarium.
But the plastic junk? Or the Fish? Or because you are interested and they are simply copying you?
Hard to say sometimes.
There's not much learned from plastic stuff, if I teach them about live plants, fish, and then take them to a national park, local pond, creek etc and point out those same things, or to the Zoo and show them, this is a far more instructive than placating their ever changing desires and "Daddy! I want this!!!"
They get their way enough. I side track them to more productive things and less destruction to my stuff. But there are other areas where they can learn a lot, I can placate them with many OTHER things. As an adult, I can guide them, I do not have to bend, rather, be creative
I was happy playing in the creek when I was their age. No plastic stuff needed. I ended up taking plants and the minnows and darters from those creeks to start this hobby.
I learned a lot more and had more fun.
As far as a dad, an adult, this is what I am still:
Ask your kids, let's go play in the creek and float down on an inner tube, or let's go buy tacky blue plastic plants?
That's a no brainer. 9 out 10 kids agree.
Good news is they change and then when they are 7-12 years old, they often get more interested in the plants/reefs etc.